diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,619 @@
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+                            Preamble
+
+  The GNU General Public License is a free, copyleft license for
+software and other kinds of works.
+
+  The licenses for most software and other practical works are designed
+to take away your freedom to share and change the works.  By contrast,
+the GNU General Public License is intended to guarantee your freedom to
+share and change all versions of a program--to make sure it remains free
+software for all its users.  We, the Free Software Foundation, use the
+GNU General Public License for most of our software; it applies also to
+any other work released this way by its authors.  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+them if you wish), that you receive source code or can get it if you
+want it, that you can change the software or use pieces of it in new
+free programs, and that you know you can do these things.
+
+  To protect your rights, we need to prevent others from denying you
+these rights or asking you to surrender the rights.  Therefore, you have
+certain responsibilities if you distribute copies of the software, or if
+you modify it: responsibilities to respect the freedom of others.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must pass on to the recipients the same
+freedoms that you received.  You must make sure that they, too, receive
+or can get the source code.  And you must show them these terms so they
+know their rights.
+
+  Developers that use the GNU GPL protect your rights with two steps:
+(1) assert copyright on the software, and (2) offer you this License
+giving you legal permission to copy, distribute and/or modify it.
+
+  For the developers' and authors' protection, the GPL clearly explains
+that there is no warranty for this free software.  For both users' and
+authors' sake, the GPL requires that modified versions be marked as
+changed, so that their problems will not be attributed erroneously to
+authors of previous versions.
+
+  Some devices are designed to deny users access to install or run
+modified versions of the software inside them, although the manufacturer
+can do so.  This is fundamentally incompatible with the aim of
+protecting users' freedom to change the software.  The systematic
+pattern of such abuse occurs in the area of products for individuals to
+use, which is precisely where it is most unacceptable.  Therefore, we
+have designed this version of the GPL to prohibit the practice for those
+products.  If such problems arise substantially in other domains, we
+stand ready to extend this provision to those domains in future versions
+of the GPL, as needed to protect the freedom of users.
+
+  Finally, every program is threatened constantly by software patents.
+States should not allow patents to restrict development and use of
+software on general-purpose computers, but in those that do, we wish to
+avoid the special danger that patents applied to a free program could
+make it effectively proprietary.  To prevent this, the GPL assures that
+patents cannot be used to render the program non-free.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+                       TERMS AND CONDITIONS
+
+  0. Definitions.
+
+  "This License" refers to version 3 of the GNU General Public License.
+
+  "Copyright" also means copyright-like laws that apply to other kinds of
+works, such as semiconductor masks.
+
+  "The Program" refers to any copyrightable work licensed under this
+License.  Each licensee is addressed as "you".  "Licensees" and
+"recipients" may be individuals or organizations.
+
+  To "modify" a work means to copy from or adapt all or part of the work
+in a fashion requiring copyright permission, other than the making of an
+exact copy.  The resulting work is called a "modified version" of the
+earlier work or a work "based on" the earlier work.
+
+  A "covered work" means either the unmodified Program or a work based
+on the Program.
+
+  To "propagate" a work means to do anything with it that, without
+permission, would make you directly or secondarily liable for
+infringement under applicable copyright law, except executing it on a
+computer or modifying a private copy.  Propagation includes copying,
+distribution (with or without modification), making available to the
+public, and in some countries other activities as well.
+
+  To "convey" a work means any kind of propagation that enables other
+parties to make or receive copies.  Mere interaction with a user through
+a computer network, with no transfer of a copy, is not conveying.
+
+  An interactive user interface displays "Appropriate Legal Notices"
+to the extent that it includes a convenient and prominently visible
+feature that (1) displays an appropriate copyright notice, and (2)
+tells the user that there is no warranty for the work (except to the
+extent that warranties are provided), that licensees may convey the
+work under this License, and how to view a copy of this License.  If
+the interface presents a list of user commands or options, such as a
+menu, a prominent item in the list meets this criterion.
+
+  1. Source Code.
+
+  The "source code" for a work means the preferred form of the work
+for making modifications to it.  "Object code" means any non-source
+form of a work.
+
+  A "Standard Interface" means an interface that either is an official
+standard defined by a recognized standards body, or, in the case of
+interfaces specified for a particular programming language, one that
+is widely used among developers working in that language.
+
+  The "System Libraries" of an executable work include anything, other
+than the work as a whole, that (a) is included in the normal form of
+packaging a Major Component, but which is not part of that Major
+Component, and (b) serves only to enable use of the work with that
+Major Component, or to implement a Standard Interface for which an
+implementation is available to the public in source code form.  A
+"Major Component", in this context, means a major essential component
+(kernel, window system, and so on) of the specific operating system
+(if any) on which the executable work runs, or a compiler used to
+produce the work, or an object code interpreter used to run it.
+
+  The "Corresponding Source" for a work in object code form means all
+the source code needed to generate, install, and (for an executable
+work) run the object code and to modify the work, including scripts to
+control those activities.  However, it does not include the work's
+System Libraries, or general-purpose tools or generally available free
+programs which are used unmodified in performing those activities but
+which are not part of the work.  For example, Corresponding Source
+includes interface definition files associated with source files for
+the work, and the source code for shared libraries and dynamically
+linked subprograms that the work is specifically designed to require,
+such as by intimate data communication or control flow between those
+subprograms and other parts of the work.
+
+  The Corresponding Source need not include anything that users
+can regenerate automatically from other parts of the Corresponding
+Source.
+
+  The Corresponding Source for a work in source code form is that
+same work.
+
+  2. Basic Permissions.
+
+  All rights granted under this License are granted for the term of
+copyright on the Program, and are irrevocable provided the stated
+conditions are met.  This License explicitly affirms your unlimited
+permission to run the unmodified Program.  The output from running a
+covered work is covered by this License only if the output, given its
+content, constitutes a covered work.  This License acknowledges your
+rights of fair use or other equivalent, as provided by copyright law.
+
+  You may make, run and propagate covered works that you do not
+convey, without conditions so long as your license otherwise remains
+in force.  You may convey covered works to others for the sole purpose
+of having them make modifications exclusively for you, or provide you
+with facilities for running those works, provided that you comply with
+the terms of this License in conveying all material for which you do
+not control copyright.  Those thus making or running the covered works
+for you must do so exclusively on your behalf, under your direction
+and control, on terms that prohibit them from making any copies of
+your copyrighted material outside their relationship with you.
+
+  Conveying under any other circumstances is permitted solely under
+the conditions stated below.  Sublicensing is not allowed; section 10
+makes it unnecessary.
+
+  3. Protecting Users' Legal Rights From Anti-Circumvention Law.
+
+  No covered work shall be deemed part of an effective technological
+measure under any applicable law fulfilling obligations under article
+11 of the WIPO copyright treaty adopted on 20 December 1996, or
+similar laws prohibiting or restricting circumvention of such
+measures.
+
+  When you convey a covered work, you waive any legal power to forbid
+circumvention of technological measures to the extent such circumvention
+is effected by exercising rights under this License with respect to
+the covered work, and you disclaim any intention to limit operation or
+modification of the work as a means of enforcing, against the work's
+users, your or third parties' legal rights to forbid circumvention of
+technological measures.
+
+  4. Conveying Verbatim Copies.
+
+  You may convey verbatim copies of the Program's source code as you
+receive it, in any medium, provided that you conspicuously and
+appropriately publish on each copy an appropriate copyright notice;
+keep intact all notices stating that this License and any
+non-permissive terms added in accord with section 7 apply to the code;
+keep intact all notices of the absence of any warranty; and give all
+recipients a copy of this License along with the Program.
+
+  You may charge any price or no price for each copy that you convey,
+and you may offer support or warranty protection for a fee.
+
+  5. Conveying Modified Source Versions.
+
+  You may convey a work based on the Program, or the modifications to
+produce it from the Program, in the form of source code under the
+terms of section 4, provided that you also meet all of these conditions:
+
+    a) The work must carry prominent notices stating that you modified
+    it, and giving a relevant date.
+
+    b) The work must carry prominent notices stating that it is
+    released under this License and any conditions added under section
+    7.  This requirement modifies the requirement in section 4 to
+    "keep intact all notices".
+
+    c) You must license the entire work, as a whole, under this
+    License to anyone who comes into possession of a copy.  This
+    License will therefore apply, along with any applicable section 7
+    additional terms, to the whole of the work, and all its parts,
+    regardless of how they are packaged.  This License gives no
+    permission to license the work in any other way, but it does not
+    invalidate such permission if you have separately received it.
+
+    d) If the work has interactive user interfaces, each must display
+    Appropriate Legal Notices; however, if the Program has interactive
+    interfaces that do not display Appropriate Legal Notices, your
+    work need not make them do so.
+
+  A compilation of a covered work with other separate and independent
+works, which are not by their nature extensions of the covered work,
+and which are not combined with it such as to form a larger program,
+in or on a volume of a storage or distribution medium, is called an
+"aggregate" if the compilation and its resulting copyright are not
+used to limit the access or legal rights of the compilation's users
+beyond what the individual works permit.  Inclusion of a covered work
+in an aggregate does not cause this License to apply to the other
+parts of the aggregate.
+
+  6. Conveying Non-Source Forms.
+
+  You may convey a covered work in object code form under the terms
+of sections 4 and 5, provided that you also convey the
+machine-readable Corresponding Source under the terms of this License,
+in one of these ways:
+
+    a) Convey the object code in, or embodied in, a physical product
+    (including a physical distribution medium), accompanied by the
+    Corresponding Source fixed on a durable physical medium
+    customarily used for software interchange.
+
+    b) Convey the object code in, or embodied in, a physical product
+    (including a physical distribution medium), accompanied by a
+    written offer, valid for at least three years and valid for as
+    long as you offer spare parts or customer support for that product
+    model, to give anyone who possesses the object code either (1) a
+    copy of the Corresponding Source for all the software in the
+    product that is covered by this License, on a durable physical
+    medium customarily used for software interchange, for a price no
+    more than your reasonable cost of physically performing this
+    conveying of source, or (2) access to copy the
+    Corresponding Source from a network server at no charge.
+
+    c) Convey individual copies of the object code with a copy of the
+    written offer to provide the Corresponding Source.  This
+    alternative is allowed only occasionally and noncommercially, and
+    only if you received the object code with such an offer, in accord
+    with subsection 6b.
+
+    d) Convey the object code by offering access from a designated
+    place (gratis or for a charge), and offer equivalent access to the
+    Corresponding Source in the same way through the same place at no
+    further charge.  You need not require recipients to copy the
+    Corresponding Source along with the object code.  If the place to
+    copy the object code is a network server, the Corresponding Source
+    may be on a different server (operated by you or a third party)
+    that supports equivalent copying facilities, provided you maintain
+    clear directions next to the object code saying where to find the
+    Corresponding Source.  Regardless of what server hosts the
+    Corresponding Source, you remain obligated to ensure that it is
+    available for as long as needed to satisfy these requirements.
+
+    e) Convey the object code using peer-to-peer transmission, provided
+    you inform other peers where the object code and Corresponding
+    Source of the work are being offered to the general public at no
+    charge under subsection 6d.
+
+  A separable portion of the object code, whose source code is excluded
+from the Corresponding Source as a System Library, need not be
+included in conveying the object code work.
+
+  A "User Product" is either (1) a "consumer product", which means any
+tangible personal property which is normally used for personal, family,
+or household purposes, or (2) anything designed or sold for incorporation
+into a dwelling.  In determining whether a product is a consumer product,
+doubtful cases shall be resolved in favor of coverage.  For a particular
+product received by a particular user, "normally used" refers to a
+typical or common use of that class of product, regardless of the status
+of the particular user or of the way in which the particular user
+actually uses, or expects or is expected to use, the product.  A product
+is a consumer product regardless of whether the product has substantial
+commercial, industrial or non-consumer uses, unless such uses represent
+the only significant mode of use of the product.
+
+  "Installation Information" for a User Product means any methods,
+procedures, authorization keys, or other information required to install
+and execute modified versions of a covered work in that User Product from
+a modified version of its Corresponding Source.  The information must
+suffice to ensure that the continued functioning of the modified object
+code is in no case prevented or interfered with solely because
+modification has been made.
+
+  If you convey an object code work under this section in, or with, or
+specifically for use in, a User Product, and the conveying occurs as
+part of a transaction in which the right of possession and use of the
+User Product is transferred to the recipient in perpetuity or for a
+fixed term (regardless of how the transaction is characterized), the
+Corresponding Source conveyed under this section must be accompanied
+by the Installation Information.  But this requirement does not apply
+if neither you nor any third party retains the ability to install
+modified object code on the User Product (for example, the work has
+been installed in ROM).
+
+  The requirement to provide Installation Information does not include a
+requirement to continue to provide support service, warranty, or updates
+for a work that has been modified or installed by the recipient, or for
+the User Product in which it has been modified or installed.  Access to a
+network may be denied when the modification itself materially and
+adversely affects the operation of the network or violates the rules and
+protocols for communication across the network.
+
+  Corresponding Source conveyed, and Installation Information provided,
+in accord with this section must be in a format that is publicly
+documented (and with an implementation available to the public in
+source code form), and must require no special password or key for
+unpacking, reading or copying.
+
+  7. Additional Terms.
+
+  "Additional permissions" are terms that supplement the terms of this
+License by making exceptions from one or more of its conditions.
+Additional permissions that are applicable to the entire Program shall
+be treated as though they were included in this License, to the extent
+that they are valid under applicable law.  If additional permissions
+apply only to part of the Program, that part may be used separately
+under those permissions, but the entire Program remains governed by
+this License without regard to the additional permissions.
+
+  When you convey a copy of a covered work, you may at your option
+remove any additional permissions from that copy, or from any part of
+it.  (Additional permissions may be written to require their own
+removal in certain cases when you modify the work.)  You may place
+additional permissions on material, added by you to a covered work,
+for which you have or can give appropriate copyright permission.
+
+  Notwithstanding any other provision of this License, for material you
+add to a covered work, you may (if authorized by the copyright holders of
+that material) supplement the terms of this License with terms:
+
+    a) Disclaiming warranty or limiting liability differently from the
+    terms of sections 15 and 16 of this License; or
+
+    b) Requiring preservation of specified reasonable legal notices or
+    author attributions in that material or in the Appropriate Legal
+    Notices displayed by works containing it; or
+
+    c) Prohibiting misrepresentation of the origin of that material, or
+    requiring that modified versions of such material be marked in
+    reasonable ways as different from the original version; or
+
+    d) Limiting the use for publicity purposes of names of licensors or
+    authors of the material; or
+
+    e) Declining to grant rights under trademark law for use of some
+    trade names, trademarks, or service marks; or
+
+    f) Requiring indemnification of licensors and authors of that
+    material by anyone who conveys the material (or modified versions of
+    it) with contractual assumptions of liability to the recipient, for
+    any liability that these contractual assumptions directly impose on
+    those licensors and authors.
+
+  All other non-permissive additional terms are considered "further
+restrictions" within the meaning of section 10.  If the Program as you
+received it, or any part of it, contains a notice stating that it is
+governed by this License along with a term that is a further
+restriction, you may remove that term.  If a license document contains
+a further restriction but permits relicensing or conveying under this
+License, you may add to a covered work material governed by the terms
+of that license document, provided that the further restriction does
+not survive such relicensing or conveying.
+
+  If you add terms to a covered work in accord with this section, you
+must place, in the relevant source files, a statement of the
+additional terms that apply to those files, or a notice indicating
+where to find the applicable terms.
+
+  Additional terms, permissive or non-permissive, may be stated in the
+form of a separately written license, or stated as exceptions;
+the above requirements apply either way.
+
+  8. Termination.
+
+  You may not propagate or modify a covered work except as expressly
+provided under this License.  Any attempt otherwise to propagate or
+modify it is void, and will automatically terminate your rights under
+this License (including any patent licenses granted under the third
+paragraph of section 11).
+
+  However, if you cease all violation of this License, then your
+license from a particular copyright holder is reinstated (a)
+provisionally, unless and until the copyright holder explicitly and
+finally terminates your license, and (b) permanently, if the copyright
+holder fails to notify you of the violation by some reasonable means
+prior to 60 days after the cessation.
+
+  Moreover, your license from a particular copyright holder is
+reinstated permanently if the copyright holder notifies you of the
+violation by some reasonable means, this is the first time you have
+received notice of violation of this License (for any work) from that
+copyright holder, and you cure the violation prior to 30 days after
+your receipt of the notice.
+
+  Termination of your rights under this section does not terminate the
+licenses of parties who have received copies or rights from you under
+this License.  If your rights have been terminated and not permanently
+reinstated, you do not qualify to receive new licenses for the same
+material under section 10.
+
+  9. Acceptance Not Required for Having Copies.
+
+  You are not required to accept this License in order to receive or
+run a copy of the Program.  Ancillary propagation of a covered work
+occurring solely as a consequence of using peer-to-peer transmission
+to receive a copy likewise does not require acceptance.  However,
+nothing other than this License grants you permission to propagate or
+modify any covered work.  These actions infringe copyright if you do
+not accept this License.  Therefore, by modifying or propagating a
+covered work, you indicate your acceptance of this License to do so.
+
+  10. Automatic Licensing of Downstream Recipients.
+
+  Each time you convey a covered work, the recipient automatically
+receives a license from the original licensors, to run, modify and
+propagate that work, subject to this License.  You are not responsible
+for enforcing compliance by third parties with this License.
+
+  An "entity transaction" is a transaction transferring control of an
+organization, or substantially all assets of one, or subdividing an
+organization, or merging organizations.  If propagation of a covered
+work results from an entity transaction, each party to that
+transaction who receives a copy of the work also receives whatever
+licenses to the work the party's predecessor in interest had or could
+give under the previous paragraph, plus a right to possession of the
+Corresponding Source of the work from the predecessor in interest, if
+the predecessor has it or can get it with reasonable efforts.
+
+  You may not impose any further restrictions on the exercise of the
+rights granted or affirmed under this License.  For example, you may
+not impose a license fee, royalty, or other charge for exercise of
+rights granted under this License, and you may not initiate litigation
+(including a cross-claim or counterclaim in a lawsuit) alleging that
+any patent claim is infringed by making, using, selling, offering for
+sale, or importing the Program or any portion of it.
+
+  11. Patents.
+
+  A "contributor" is a copyright holder who authorizes use under this
+License of the Program or a work on which the Program is based.  The
+work thus licensed is called the contributor's "contributor version".
+
+  A contributor's "essential patent claims" are all patent claims
+owned or controlled by the contributor, whether already acquired or
+hereafter acquired, that would be infringed by some manner, permitted
+by this License, of making, using, or selling its contributor version,
+but do not include claims that would be infringed only as a
+consequence of further modification of the contributor version.  For
+purposes of this definition, "control" includes the right to grant
+patent sublicenses in a manner consistent with the requirements of
+this License.
+
+  Each contributor grants you a non-exclusive, worldwide, royalty-free
+patent license under the contributor's essential patent claims, to
+make, use, sell, offer for sale, import and otherwise run, modify and
+propagate the contents of its contributor version.
+
+  In the following three paragraphs, a "patent license" is any express
+agreement or commitment, however denominated, not to enforce a patent
+(such as an express permission to practice a patent or covenant not to
+sue for patent infringement).  To "grant" such a patent license to a
+party means to make such an agreement or commitment not to enforce a
+patent against the party.
+
+  If you convey a covered work, knowingly relying on a patent license,
+and the Corresponding Source of the work is not available for anyone
+to copy, free of charge and under the terms of this License, through a
+publicly available network server or other readily accessible means,
+then you must either (1) cause the Corresponding Source to be so
+available, or (2) arrange to deprive yourself of the benefit of the
+patent license for this particular work, or (3) arrange, in a manner
+consistent with the requirements of this License, to extend the patent
+license to downstream recipients.  "Knowingly relying" means you have
+actual knowledge that, but for the patent license, your conveying the
+covered work in a country, or your recipient's use of the covered work
+in a country, would infringe one or more identifiable patents in that
+country that you have reason to believe are valid.
+
+  If, pursuant to or in connection with a single transaction or
+arrangement, you convey, or propagate by procuring conveyance of, a
+covered work, and grant a patent license to some of the parties
+receiving the covered work authorizing them to use, propagate, modify
+or convey a specific copy of the covered work, then the patent license
+you grant is automatically extended to all recipients of the covered
+work and works based on it.
+
+  A patent license is "discriminatory" if it does not include within
+the scope of its coverage, prohibits the exercise of, or is
+conditioned on the non-exercise of one or more of the rights that are
+specifically granted under this License.  You may not convey a covered
+work if you are a party to an arrangement with a third party that is
+in the business of distributing software, under which you make payment
+to the third party based on the extent of your activity of conveying
+the work, and under which the third party grants, to any of the
+parties who would receive the covered work from you, a discriminatory
+patent license (a) in connection with copies of the covered work
+conveyed by you (or copies made from those copies), or (b) primarily
+for and in connection with specific products or compilations that
+contain the covered work, unless you entered into that arrangement,
+or that patent license was granted, prior to 28 March 2007.
+
+  Nothing in this License shall be construed as excluding or limiting
+any implied license or other defenses to infringement that may
+otherwise be available to you under applicable patent law.
+
+  12. No Surrender of Others' Freedom.
+
+  If conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot convey a
+covered work so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you may
+not convey it at all.  For example, if you agree to terms that obligate you
+to collect a royalty for further conveying from those to whom you convey
+the Program, the only way you could satisfy both those terms and this
+License would be to refrain entirely from conveying the Program.
+
+  13. Use with the GNU Affero General Public License.
+
+  Notwithstanding any other provision of this License, you have
+permission to link or combine any covered work with a work licensed
+under version 3 of the GNU Affero General Public License into a single
+combined work, and to convey the resulting work.  The terms of this
+License will continue to apply to the part which is the covered work,
+but the special requirements of the GNU Affero General Public License,
+section 13, concerning interaction through a network will apply to the
+combination as such.
+
+  14. Revised Versions of this License.
+
+  The Free Software Foundation may publish revised and/or new versions of
+the GNU General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+  Each version is given a distinguishing version number.  If the
+Program specifies that a certain numbered version of the GNU General
+Public License "or any later version" applies to it, you have the
+option of following the terms and conditions either of that numbered
+version or of any later version published by the Free Software
+Foundation.  If the Program does not specify a version number of the
+GNU General Public License, you may choose any version ever published
+by the Free Software Foundation.
+
+  If the Program specifies that a proxy can decide which future
+versions of the GNU General Public License can be used, that proxy's
+public statement of acceptance of a version permanently authorizes you
+to choose that version for the Program.
+
+  Later license versions may give you additional or different
+permissions.  However, no additional obligations are imposed on any
+author or copyright holder as a result of your choosing to follow a
+later version.
+
+  15. Disclaimer of Warranty.
+
+  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
+HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
+OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
+IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
diff --git a/Setup.hs b/Setup.hs
new file mode 100644
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/bench/Bench.hs b/bench/Bench.hs
new file mode 100644
--- /dev/null
+++ b/bench/Bench.hs
@@ -0,0 +1,9 @@
+module Main where
+
+import           Criterion.Main                 (bgroup, defaultMain)
+import qualified Data.HdrHistogram.MutableBench as M
+
+main :: IO ()
+main = defaultMain [
+  bgroup "Data.HdrHistogram.Mutable" M.benchmarks
+  ]
diff --git a/bench/Data/HdrHistogram/MutableBench.hs b/bench/Data/HdrHistogram/MutableBench.hs
new file mode 100644
--- /dev/null
+++ b/bench/Data/HdrHistogram/MutableBench.hs
@@ -0,0 +1,27 @@
+{-# LANGUAGE DataKinds #-}
+module Data.HdrHistogram.MutableBench (benchmarks) where
+
+import           Control.Monad             (forM_)
+import           Control.Monad.Primitive   (PrimMonad, PrimState)
+import           Criterion.Main
+import           Data.HdrHistogram.Config
+import qualified Data.HdrHistogram.Mutable as MH
+
+type Config' = Config 1 3600000000 3
+
+insertRange :: PrimMonad m => Int -> MH.Histogram (PrimState m) Config' Int Int -> m (MH.Histogram (PrimState m) Config' Int Int)
+insertRange r h = do
+  forM_ [1..r] $ MH.record h
+  return h
+
+benchmarks :: [Benchmark]
+benchmarks = [
+  env MH.new $ \h ->
+    bgroup "insert" [
+       bench "1" $ nfIO (MH.record h 12000 >> return h),
+       bench "10" $ nfIO (insertRange 10 h),
+       bench "100" $ nfIO (insertRange 100 h),
+       bench "1000" $ nfIO (insertRange 1000 h),
+       bench "10000" $ nfIO (insertRange 10000 h)
+      ]
+  ]
diff --git a/hdr-histogram.cabal b/hdr-histogram.cabal
new file mode 100644
--- /dev/null
+++ b/hdr-histogram.cabal
@@ -0,0 +1,78 @@
+name:                hdr-histogram
+version:             0.1.0.0
+synopsis:            Haskell implementation of High Dynamic Range (HDR) Histograms
+description:         Please see README.md
+homepage:            http://github.com/joshbohde/hdr-histogram#readme
+bug-reports:         http://github.com/joshbohde/hdr-histogram/issues
+license:             GPL-3
+license-file:        LICENSE
+author:              Josh Bohde <josh@joshbohde.com>
+maintainer:          Josh Bohde <josh@joshbohde.com>
+copyright:           2015 Josh Bohde
+category:            Math, Statistics
+build-type:          Simple
+-- extra-source-files:
+cabal-version:       >=1.10
+
+library
+  hs-source-dirs:      src
+  exposed-modules:     Data.HdrHistogram
+                       Data.HdrHistogram.Config
+                       Data.HdrHistogram.Config.Internal
+                       Data.HdrHistogram.Mutable
+                       Data.HdrHistogram.Tutorial
+  build-depends:       base >= 4.7 && < 5
+                     , vector >= 0.10 && < 0.12
+                     , primitive >= 0.6 && < 0.7
+                     , deepseq >= 1.4 && < 1.5
+                     , tagged >= 0.8 && < 0.9
+                     , QuickCheck
+  default-language:    Haskell2010
+  ghc-options:         -Wall -O2
+
+test-suite hdr-histogram-test
+  type:                exitcode-stdio-1.0
+  hs-source-dirs:      test
+  main-is:             Spec.hs
+  other-modules:
+                       Data.HdrHistogramSpec
+                       Data.HdrHistogram.ConfigSpec
+                       Data.HdrHistogram.MutableSpec
+                       Test.Expectations
+                       Test.Utils
+  build-depends:       base
+                     , hdr-histogram
+                     , hspec
+                     , QuickCheck
+                     , random
+                     , tagged
+                     , vector
+                     , vector-algorithms
+  ghc-options:         -Wall -threaded -rtsopts -with-rtsopts=-N
+  default-language:    Haskell2010
+
+
+benchmark hdr-histogram-bench
+  type:                exitcode-stdio-1.0
+  hs-source-dirs:      bench
+  main-is:             Bench.hs
+  other-modules:
+                       Data.HdrHistogram.MutableBench
+  build-depends:       base
+                     , hdr-histogram
+                     , deepseq
+                     , criterion
+                     , primitive
+  ghc-options:         -Wall
+                       -O2
+                       -fmax-simplifier-iterations=10
+                       -fdicts-cheap
+                       -fspec-constr-count=6
+                       -threaded
+                       -rtsopts
+                       -with-rtsopts=-T
+  default-language:    Haskell2010
+
+source-repository head
+  type:     git
+  location: https://github.com/joshbohde/hdr-histogram
diff --git a/src/Data/HdrHistogram.hs b/src/Data/HdrHistogram.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/HdrHistogram.hs
@@ -0,0 +1,100 @@
+{-|
+Module      : Data.HdrHistogram
+Copyright   : (c) Josh Bohde, 2015
+License     : GPL-3
+Maintainer  : josh@joshbohde.com
+Stability   : experimental
+Portability : POSIX
+
+A Haskell implementation of <http://www.hdrhistogram.org/ HdrHistogram>.
+It allows storing counts of observed values within a range,
+while maintaining precision to a configurable number of significant
+digits.
+
+-}
+{-# LANGUAGE FlexibleContexts    #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+module Data.HdrHistogram (
+  -- * Histogram
+  Histogram(..), empty, fromConfig,
+  -- * Writing
+  record, recordValues,
+  -- * Reading
+  Range(..),
+  percentile,
+  -- * Re-exports
+  Config, HasConfig
+  ) where
+
+import           Data.Bits                         (Bits, FiniteBits)
+import           Data.HdrHistogram.Config
+import           Data.HdrHistogram.Config.Internal
+import           Data.Proxy                        (Proxy (Proxy))
+import           Data.Tagged                       (Tagged (Tagged))
+import           Data.Vector.Unboxed               ((!), (//))
+import qualified Data.Vector.Unboxed               as U
+
+-- | A pure 'Histogram'
+data Histogram config value count = Histogram {
+  _config    :: HistogramConfig value,
+  totalCount :: count,
+  counts     :: U.Vector count
+} deriving (Eq, Show)
+
+-- | Construct a 'Histogram'.
+empty :: forall config value count. (HasConfig config, Integral value, FiniteBits value, U.Unbox count, Integral count) => Histogram config value count
+empty = fromConfig (Tagged c :: Tagged config (HistogramConfig value))
+  where
+    p = Proxy :: Proxy config
+    c = getConfig p
+
+-- | Construct a 'Histogram' from the given 'HistogramConfig'. In this
+-- case 'c' is a phantom type.
+fromConfig :: (U.Unbox count, Integral count) => Tagged c (HistogramConfig value) -> Histogram c value count
+fromConfig (Tagged c) = Histogram {
+  _config = c,
+  totalCount = 0,
+  counts = U.replicate (size c) 0
+  }
+
+instance (HasConfig config, Integral value, FiniteBits value, U.Unbox count, Integral count) =>
+         Monoid (Histogram config value count) where
+  mempty = empty
+  Histogram config' t c `mappend` Histogram _ t' c' = Histogram config' (t + t') (U.zipWith (+) c c')
+
+-- | Record a single value to the 'Histogram'
+record :: (U.Unbox count,
+          Integral count, Integral value, FiniteBits value)
+         => Histogram config value count
+         -> value
+         -> Histogram config value count
+record h val = recordValues h val 1
+
+-- | Record a multiple instances of a value value to the 'Histogram'
+recordValues :: (U.Unbox count, Integral count, Integral value, FiniteBits value) => Histogram config value count -> value -> count -> Histogram config value count
+recordValues h val count = h {
+    totalCount = totalCount h + count,
+    counts = counts h // [(index, (counts h ! index) + count)]
+    }
+  where
+    index = indexForValue (_config h) val
+
+-- recordCorrectedValues :: Integral value => Histogram value count -> value -> value -> Histogram value count
+-- recordCorrectedValues = undefined
+
+-- | Calculate the 'Range' of values at the given percentile
+percentile :: (Integral value, Integral count, U.Unbox count, Bits value)
+             => Histogram config value count
+             -> Float -- ^ The percentile in the range 0 to 100
+             -> Range value
+percentile h q = case U.find ((>= count) . snd) totals of
+  Nothing -> Range 0 0
+  Just (i, _) -> rangeForIndex c i
+  where
+    c = _config h
+    q' = min q 100
+    count = floor $ (q' / 100) * fromIntegral (totalCount h) + 0.5
+    totals = U.scanl f (0 :: Int, 0) withIndex
+      where
+        f (_, v') (i, v) = (i, v' + v)
+        withIndex = U.imap (,) (counts h)
diff --git a/src/Data/HdrHistogram/Config.hs b/src/Data/HdrHistogram/Config.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/HdrHistogram/Config.hs
@@ -0,0 +1,72 @@
+{-|
+Module      : Data.HdrHistogram.Config
+Copyright   : (c) Josh Bohde, 2015
+License     : GPL-3
+Maintainer  : josh@joshbohde.com
+Stability   : experimental
+Portability : POSIX
+
+A Haskell implementation of <http://www.hdrhistogram.org/ HdrHistogram>. It allows storing counts of observed values within a range,
+while maintaining precision to a configurable number of significant
+digits.
+
+This module captures the common functionality of converting values to
+and from 'Int' indices, regardless of mutability or memory layout.
+-}
+{-# LANGUAGE ConstraintKinds     #-}
+{-# LANGUAGE DataKinds           #-}
+{-# LANGUAGE KindSignatures      #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE FlexibleContexts    #-}
+{-# LANGUAGE TypeFamilies        #-}
+{-# LANGUAGE TypeOperators       #-}
+module Data.HdrHistogram.Config (
+  -- * Config
+  Config, HighLow, SigBounds,
+  HasConfig(getConfig),
+  -- * HistogramConfig
+  size,
+  indexForValue,
+  Range(..),
+  rangeForIndex
+  ) where
+
+import           Data.Bits                         (Bits, FiniteBits)
+import Data.Proxy (Proxy(Proxy))
+import           GHC.TypeLits (KnownNat, Nat, type (<=), type (-), natVal)
+import           Data.HdrHistogram.Config.Internal
+
+{- $Config -}
+-- | Type-safe configuration for a Histogram
+data Config (lowest :: Nat) (highest :: Nat) (sig :: Nat)
+
+type HighLow a b = (a <= (b - 1))
+
+-- | Significant Figures must be between 1 & 5
+type SigBounds sig = (1 <= sig, sig <= 5)
+
+-- | Typeclass to specify the types which can produce a HistogramConfig
+class HasConfig s where
+  getConfig :: (Integral a, FiniteBits a) => Proxy s -> HistogramConfig a
+
+instance (KnownNat low, KnownNat high, KnownNat sig, HighLow low high, SigBounds sig) =>
+         HasConfig (Config low high sig) where
+  {-# INLINEABLE getConfig #-}
+  getConfig _ = config low' high' (SignificantFigures sig')
+    where
+      low' = fromIntegral $ natVal $ (Proxy :: Proxy low)
+      high' = fromIntegral $ natVal $ (Proxy :: Proxy high)
+      sig' = fromIntegral $ natVal $ (Proxy :: Proxy sig)
+
+{- $HistogramConfig -}
+{-# INLINEABLE indexForValue #-}
+-- | The index for a value
+indexForValue :: (FiniteBits a, Integral a) =>
+                HistogramConfig a -> a -> Int
+indexForValue c = asInt c . asIndex c
+
+{-# INLINEABLE rangeForIndex #-}
+-- | The possible range of values for a given index
+rangeForIndex :: (Integral a, Bits a) =>
+                HistogramConfig a -> Int -> Range a
+rangeForIndex c = fromIndex c . fromInt c
diff --git a/src/Data/HdrHistogram/Config/Internal.hs b/src/Data/HdrHistogram/Config/Internal.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/HdrHistogram/Config/Internal.hs
@@ -0,0 +1,186 @@
+{-# LANGUAGE DeriveGeneric              #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE ScopedTypeVariables        #-}
+module Data.HdrHistogram.Config.Internal (
+  HistogramConfig, config, lowest, highest, sigFigures, bucketCount, subBucketCount, size,
+  SignificantFigures(..),
+  significantFigures,
+  Range(..),
+  Index(..),
+  asInt, fromInt,
+  asIndex, fromIndex,
+  bitLength
+  ) where
+
+import           Control.DeepSeq (NFData)
+import           Data.Bits       (Bits, FiniteBits, bitSizeMaybe,
+                                  countLeadingZeros, finiteBitSize, shift,
+                                  shiftR, (.&.), (.|.))
+import           GHC.Generics    (Generic)
+import           Test.QuickCheck (Arbitrary (..), Large (..), Positive (..),
+                                  elements, getLarge, suchThat)
+
+-- | The number of significant figures for recorded values
+newtype SignificantFigures = SignificantFigures Int deriving (Eq, Show, NFData)
+
+-- | Construct a 'SignificantFigures'. Valid values are between 1 and 5
+significantFigures :: Int -> Either String SignificantFigures
+significantFigures i = if i > 0  && i < 6
+  then Right $ SignificantFigures i
+  else Left "HdrHistogram.significantFigures must be between 1 and 5"
+
+instance Arbitrary SignificantFigures where
+  arbitrary = SignificantFigures <$> elements [1..5]
+  shrink (SignificantFigures a) = fmap SignificantFigures [1..(a - 1)]
+
+-- | Supporting data to transform a value from 'a' within a range of
+-- `lowest` to `highest`, while maintaining `sigFigures` amount of
+-- precision, to an 'Int'.
+data HistogramConfig a = HistogramConfig {
+   -- | The lowest expected recorded value
+   lowest                      :: !a,
+   -- | The highest expected recorded value
+   highest                     :: !a,
+   -- | The number of significant figures for recorded values
+   sigFigures                  :: !SignificantFigures,
+   unitMagnitude               :: !Int,
+   subBucketHalfCountMagnitude :: !Int,
+   subBucketHalfCount          :: !Int,
+   subBucketMask               :: !a,
+   -- | the total number sub buckets per bucket
+   subBucketCount              :: !Int,
+   -- | the total number of buckets
+   bucketCount                 :: !Int,
+   -- | the total number of elements distinct indices
+   size                        :: !Int
+   } deriving (Eq, Show, Generic)
+
+instance (NFData a) => NFData (HistogramConfig a)
+
+instance (Arbitrary a, Bounded a, Integral a, Bits a) => Arbitrary (HistogramConfig a) where
+  arbitrary = do
+    (Positive min') <- arbitrary
+    (Large max') <- arbitrary `suchThat` ((> min') . getLarge)
+    s <- arbitrary
+    return $ config min' max' s
+
+  shrink c = filter (/= c) vals
+    where
+      vals = do
+        min' <- [0..lowest c]
+        max' <- [min'+1..highest c]
+        s <- shrink $ sigFigures c
+        return $ config min' max' s
+
+-- | A range of values between 'lower' and 'upper'
+data Range a = Range {
+  lower :: a,
+  upper :: a
+  } deriving (Show, Eq)
+
+-- | smart constructor for 'HistogramConfig'
+config :: forall a. (Integral a, Bits a)
+         => a -- ^ The lowest recordable value
+         -> a -- ^ The highest recordable value
+         -> SignificantFigures
+         -> HistogramConfig a
+config lowest' highest' s@(SignificantFigures sigfigs) = config'
+  where
+    config' = HistogramConfig {
+      lowest = lowest',
+      highest = highest',
+      sigFigures = s,
+      unitMagnitude = unitMagnitude',
+      subBucketHalfCountMagnitude = subBucketHalfCountMagnitude',
+      subBucketHalfCount          = floor $ subBucketCount' / 2,
+      subBucketMask               = floor (subBucketCount' - 1) `shift` unitMagnitude',
+      subBucketCount              = floor subBucketCount',
+      bucketCount                 = bucketCount',
+      size                        = size'
+      }
+
+    toDouble :: (Real b) => b -> Double
+    toDouble = fromRational . toRational
+
+    unitMagnitude' = fromInteger $ floor $ max 0 m
+      where
+        m = logBase 2 (toDouble lowest')
+
+    subBucketHalfCountMagnitude' :: Int
+    subBucketHalfCountMagnitude' = max 0 (magnitude - 1)
+      where
+        desiredMagnitude = (ceiling . logBase 2 . (* 2) . (10 **) . toDouble) sigfigs
+        magnitude = case bitSizeMaybe (0 :: a) of
+          Nothing -> desiredMagnitude
+          Just i ->  min possibleMagnitude desiredMagnitude
+            where
+              possibleMagnitude = i - 1 - unitMagnitude'
+
+
+    subBucketCount' :: Double
+    subBucketCount' = 2 ** fromIntegral (subBucketHalfCountMagnitude' + 1)
+
+    bucketCount' :: Int
+    bucketCount' = 1 + length (takeWhile (< effectiveHighest) $ iterate (`shift` 1) smallestUntrackable)
+      where
+        effectiveHighest :: Integer
+        effectiveHighest = fromIntegral highest'
+        smallestUntrackable :: Integer
+        smallestUntrackable = floor subBucketCount' `shift` unitMagnitude'
+
+    size' = (bucketCount' + 1) * floor (subBucketCount' / 2)
+
+-- | An 'HistogramConfig' specific internal representation of an index
+data Index = Index {
+  bucket    :: Int,
+  subBucket :: Int
+  }
+
+{-# INLINEABLE asInt #-}
+asInt :: HistogramConfig a -> Index -> Int
+asInt c (Index b sub) = (sub' + bucket') - 1
+  where
+    sub' = sub - subBucketHalfCount c
+    bucket' = (b + 1) `shift` subBucketHalfCountMagnitude c
+
+fromInt :: HistogramConfig a -> Int -> Index
+fromInt c i = if bucket' < 0
+              then Index 0 (sub' - subBucketHalfCount c)
+              else Index bucket' sub'
+  where
+    i' = i + 1
+    bucket' = (i' `shiftR` subBucketHalfCountMagnitude c) - 1
+    sub' = i' .&. (subBucketHalfCount c - 1) + subBucketHalfCount c
+
+
+{-# INLINEABLE asIndex #-}
+asIndex :: (Integral a, FiniteBits a) => HistogramConfig a -> a -> Index
+asIndex c a = Index bucket' sub
+  where
+    magnitude :: Int
+    magnitude = unitMagnitude c
+
+    bucket' = m - (subBucketHalfCountMagnitude c + 1)
+      where
+        m :: Int
+        m = bitLength (a .|. subBucketMask c) - magnitude
+
+    sub = fromIntegral $ a `shiftR` toShift
+      where
+        toShift :: Int
+        toShift = bucket' + magnitude
+
+-- | The range of possible values represented by this Index
+fromIndex :: (Integral a, Bits a) => HistogramConfig a -> Index -> Range a
+fromIndex c (Index bucket' sub) = Range lower' upper'
+  where
+    toShift = bucket' + unitMagnitude c
+    lower' = fromIntegral $ sub `shift` toShift
+    range = 1 `shift` toShift
+    upper' = (lower' + range) - 1
+
+{-# INLINEABLE bitLength #-}
+-- | The number of bits required to represent this data, disregarding
+-- leading zeros
+bitLength :: FiniteBits b => b -> Int
+bitLength b = finiteBitSize b - countLeadingZeros b
diff --git a/src/Data/HdrHistogram/Mutable.hs b/src/Data/HdrHistogram/Mutable.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/HdrHistogram/Mutable.hs
@@ -0,0 +1,131 @@
+{-|
+Module      : Data.HdrHistogram.Mutable
+Copyright   : (c) Josh Bohde, 2015
+License     : GPL-3
+Maintainer  : josh@joshbohde.com
+Stability   : experimental
+Portability : POSIX
+
+A Haskell implementation of <http://www.hdrhistogram.org/ HdrHistogram>.
+It allows storing counts of observed values within a range,
+while maintaining precision to a configurable number of significant
+digits.
+
+The mutable histogram allows only writes, and conversion to and from
+pure histograms. It follows the original implementation, and has
+similar performance characteristics. Current recording benchmarks take
+about 9ns, and allocates 16 bytes.
+
+-}
+{-# LANGUAGE DeriveGeneric       #-}
+{-# LANGUAGE FlexibleContexts    #-}
+{-# LANGUAGE RankNTypes          #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+module Data.HdrHistogram.Mutable (
+  -- * Histogram
+  Histogram(..), new, fromConfig,
+
+  -- * Writing
+  record, recordValues,
+
+  -- * Converting
+  freeze, unsafeFreeze, thaw, unsafeThaw,
+
+  -- * Re-exports
+  Config, HasConfig
+  ) where
+
+import           Control.DeepSeq                   (NFData, deepseq, rnf)
+import           Control.Monad.Primitive           (PrimMonad, PrimState)
+import           Data.Bits                         (FiniteBits)
+import qualified Data.HdrHistogram                 as H
+import           Data.HdrHistogram.Config
+import           Data.HdrHistogram.Config.Internal
+import           Data.Primitive.MutVar             (MutVar, modifyMutVar',
+                                                    newMutVar, readMutVar)
+import           Data.Proxy                        (Proxy (Proxy))
+import           Data.Tagged                       (Tagged (Tagged))
+import qualified Data.Vector.Unboxed               as U
+import qualified Data.Vector.Unboxed.Mutable       as MU
+import           GHC.Generics                      (Generic)
+
+-- | A mutable 'Histogram'
+data Histogram s c value count = Histogram {
+  _config    :: HistogramConfig value,
+  totalCount :: MutVar s count,
+  counts     :: U.MVector s count
+} deriving (Generic)
+
+instance (NFData value, NFData count) => NFData (Histogram s config value count) where
+  rnf (Histogram c _ vec) = deepseq c $ deepseq vec ()
+
+-- | Construct a 'Histogram'
+new :: forall m config a count.
+      (PrimMonad m, HasConfig config,
+       Integral a, FiniteBits a,
+       U.Unbox count, Integral count) =>
+      m (Histogram (PrimState m) config a count)
+new = fromConfig (Tagged c :: Tagged config (HistogramConfig a))
+  where
+    c = getConfig p
+    p = Proxy :: Proxy config
+
+-- | Construct a 'Histogram' from the given 'HistogramConfig'. In this
+-- case 'c' is a phantom type.
+fromConfig :: (PrimMonad m, U.Unbox count, Integral count) => Tagged c (HistogramConfig value) -> m (Histogram (PrimState m) c value count)
+fromConfig (Tagged c) = do
+  vect <- MU.replicate (size c) 0
+  totals <- newMutVar 0
+  return Histogram {
+    _config = c,
+    totalCount = totals,
+    counts = vect
+  }
+
+
+{-# INLINEABLE record #-}
+-- | Record value single value to the 'Histogram'
+record :: (Integral value, Integral count, FiniteBits value, U.Unbox count, PrimMonad m) =>
+         Histogram (PrimState m) c value count -> value -> m ()
+record h val = recordValues h val 1
+
+{-# INLINEABLE recordValues #-}
+-- | Record a multiple instances of a value value to the 'Histogram'
+recordValues :: (Integral value, Integral count, FiniteBits value, U.Unbox count, PrimMonad m) =>
+               Histogram (PrimState m) config value count -> value -> count -> m ()
+recordValues h val count = do
+  modifyMutVar' (totalCount h) (+ count)
+  modify (counts h) (+ count) (indexForValue c val)
+  where
+    c = _config h
+    modify v f i = do
+      a <- MU.unsafeRead v i
+      MU.unsafeWrite v i (f a)
+
+-- | Convert a mutable 'Histogram' to a pure 'Histogram'
+freeze :: (MU.Unbox count, PrimMonad m) => Histogram (PrimState m) config value count -> m (H.Histogram config value count)
+freeze (Histogram c total vec) = do
+  t <- readMutVar total
+  v <- U.freeze vec
+  return $ H.Histogram c t v
+
+-- | Convert a mutable 'Histogram' to a pure 'Histogram'. The mutable cannot counte reused after this.
+unsafeFreeze :: (MU.Unbox count, PrimMonad m) => Histogram (PrimState m) config value count -> m (H.Histogram config value count)
+unsafeFreeze (Histogram c total vec) = do
+  t <- readMutVar total
+  v <- U.unsafeFreeze vec
+  return $ H.Histogram c t v
+
+-- | Convert a pure 'Histogram' to a mutable 'Histogram'.
+thaw :: (MU.Unbox count, PrimMonad m) => H.Histogram config value count -> m (Histogram (PrimState m) config value count)
+thaw (H.Histogram c total vec) = do
+  t <- newMutVar total
+  v <- U.thaw vec
+  return $ Histogram c t v
+
+-- | Convert a pure 'Histogram' to a mutable 'Histogram'. The pure cannot counte reused after this.
+unsafeThaw :: (MU.Unbox count, PrimMonad m) => H.Histogram config value count -> m (Histogram (PrimState m) config value count)
+unsafeThaw (H.Histogram c total vec) = do
+  t <- newMutVar total
+  v <- U.unsafeThaw vec
+  return $ Histogram c t v
diff --git a/src/Data/HdrHistogram/Tutorial.hs b/src/Data/HdrHistogram/Tutorial.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/HdrHistogram/Tutorial.hs
@@ -0,0 +1,44 @@
+{-|
+Module      : Data.HdrHistogram.Tutorial
+Copyright   : (c) Josh Bohde, 2015
+License     : GPL-3
+Maintainer  : josh@joshbohde.com
+Stability   : experimental
+Portability : POSIX
+
+-}
+{-# LANGUAGE DataKinds           #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
+
+module Data.HdrHistogram.Tutorial (
+  -- * Example
+  -- $example
+  ) where
+
+import           Control.Monad             (forM_)
+import qualified Data.HdrHistogram         as H
+import qualified Data.HdrHistogram.Mutable as MH
+
+{- $example
+> {-# LANGUAGE DataKinds           #-}
+> {-# LANGUAGE ScopedTypeVariables #-}
+>
+> import           Control.Monad             (forM_)
+> import qualified Data.HdrHistogram         as H
+> import qualified Data.HdrHistogram.Mutable as MH
+>
+> vals :: [Int]
+> vals = undefined
+>
+> -- Measure from 1ms to 1 hour, with 3 points of precision
+> type Config = H.Config 1 3600000 3
+>
+> main :: IO ()
+> main = do
+>   h <- MH.new
+>   forM_ vals (MH.record h)
+>   (frozen :: H.Histogram Config Int Int) <- MH.freeze h
+>   print $ H.percentile frozen 50
+>
+-}
diff --git a/test/Data/HdrHistogram/ConfigSpec.hs b/test/Data/HdrHistogram/ConfigSpec.hs
new file mode 100644
--- /dev/null
+++ b/test/Data/HdrHistogram/ConfigSpec.hs
@@ -0,0 +1,96 @@
+{-# LANGUAGE ScopedTypeVariables #-}
+module Data.HdrHistogram.ConfigSpec where
+
+import           Data.Bits                         (Bits, FiniteBits)
+import           Data.HdrHistogram.Config.Internal
+import qualified Data.Int                          as Int
+import qualified Data.Word                         as Word
+import           System.Random                     (Random)
+import           Test.Expectations
+import           Test.Hspec
+import           Test.Hspec.QuickCheck             (prop)
+import           Test.QuickCheck
+
+data ConfigAndVal a = ConfigAndVal (HistogramConfig a) a
+                    deriving (Show, Eq)
+
+instance (Random a, Arbitrary a, Bounded a, Integral a, Bits a) => Arbitrary (ConfigAndVal a) where
+  arbitrary = do
+    config' <- arbitrary
+    val <- choose (lowest config', highest config')
+    return $ ConfigAndVal config' val
+
+data ConfigAndIndex a = ConfigAndIndex (HistogramConfig a) Int
+                    deriving (Show, Eq)
+
+instance (Random a, Arbitrary a, Bounded a, Integral a, Bits a) => Arbitrary (ConfigAndIndex a) where
+  arbitrary = do
+    config' <- arbitrary
+    i <- choose (0, size config' - 1)
+    return $ ConfigAndIndex config' i
+
+
+data SpecType a = SpecType Spec
+
+runSpecType :: SpecType a -> Spec
+runSpecType (SpecType s) = s
+
+typeSpec :: forall a. (Show a, Integral a, Random a, Arbitrary a, Bounded a, FiniteBits a) => SpecType a
+typeSpec = SpecType $ do
+  prop "should generate bucket indices in bounds" $ \(ConfigAndVal config' (val :: a)) -> do
+    let
+      bi = asIndex config' val
+      i = asInt config' bi
+    bucket bi `shouldBeLessThan` bucketCount config'
+    bucket bi `shouldBeGreaterThanOrEqual` 0
+    subBucket bi `shouldBeLessThan` subBucketCount config'
+    subBucket bi `shouldBeGreaterThanOrEqual` 0
+    i `shouldBeLessThan` size config'
+    i `shouldBeGreaterThanOrEqual` 0
+
+  prop "index 0 should contain the lowest value" $ \(config' :: HistogramConfig a) -> do
+    let
+      val' = fromIndex config' $ fromInt config' 0
+    upper val' `shouldBeGreaterThanOrEqual` lowest config'
+    lower val' `shouldBeLessThanOrEqual` lowest config'
+
+  prop "highest index should contain the highest value" $ \(config' :: HistogramConfig a) -> do
+    pendingWith "Unsure this property should hold"
+    let
+      val' = fromIndex config' $ fromInt config' (size config' - 1)
+    upper val' `shouldBeGreaterThanOrEqual` highest config'
+    lower val' `shouldBeLessThanOrEqual` highest config'
+
+  prop "asInt . fromInt == id" $ \(ConfigAndIndex (c :: HistogramConfig a) i) ->
+    (asInt c . fromInt c) i `shouldBe` i
+
+  prop "fromIndex . asIndex should give contain value" $ \(ConfigAndVal c (val :: a)) -> do
+    let
+      range = (fromIndex c . asIndex c) val
+    upper range `shouldBeGreaterThanOrEqual` val
+    lower range `shouldBeLessThanOrEqual` val
+
+spec :: Spec
+spec = do
+  describe "bitLength" $ do
+    it "should match the reference" $ do
+      bitLength (0x1 :: Int) `shouldBe` 1
+      bitLength (0x2 :: Int) `shouldBe` 2
+      bitLength (0x4 :: Int) `shouldBe` 3
+      bitLength (0x1000 :: Int) `shouldBe` 13
+      bitLength (0x1000000 :: Int) `shouldBe` (64 - 39)
+
+    prop "should return the smallest power of two containing the value"
+      $ \(NonNegative a) -> do
+      let
+        i = fromIntegral (bitLength a)
+      floor ((2 :: Double) ** i) `shouldBeGreaterThan` (a :: Int)
+      floor (2 ** (i - 1)) `shouldBeLessThanOrEqual` (a :: Int)
+
+  describe "HistogramConfig Int" $ runSpecType (typeSpec :: SpecType Int)
+  describe "HistogramConfig Int16" $ runSpecType (typeSpec :: SpecType Int.Int16)
+  describe "HistogramConfig Int32" $ runSpecType (typeSpec :: SpecType Int.Int32)
+  describe "HistogramConfig Int64" $ runSpecType (typeSpec :: SpecType Int.Int64)
+  describe "HistogramConfig Word16" $ runSpecType (typeSpec :: SpecType Word.Word16)
+  describe "HistogramConfig Word32" $ runSpecType (typeSpec :: SpecType Word.Word32)
+  describe "HistogramConfig Word64" $ runSpecType (typeSpec :: SpecType Word.Word64)
diff --git a/test/Data/HdrHistogram/MutableSpec.hs b/test/Data/HdrHistogram/MutableSpec.hs
new file mode 100644
--- /dev/null
+++ b/test/Data/HdrHistogram/MutableSpec.hs
@@ -0,0 +1,27 @@
+{-# LANGUAGE ScopedTypeVariables #-}
+module Data.HdrHistogram.MutableSpec where
+
+import           Control.Monad.ST          (runST)
+import           Data.HdrHistogram
+import qualified Data.HdrHistogram.Mutable as MH
+import qualified Data.Vector               as U
+import           Test.Expectations
+import           Test.Hspec
+import           Test.Hspec.QuickCheck     (prop)
+import           Test.Utils
+
+spec :: Spec
+spec =
+  describe "Histogram" $
+    prop "should be close to reference implementation" $ \((ConfigAndVals c vals) :: ConfigAndVals c Int) -> do
+      let
+        v = U.fromList vals
+        median' = median v
+        h :: Histogram c Int Int
+        h = runST $ do
+          h' <- MH.fromConfig c
+          U.forM_ v (MH.record h')
+          MH.unsafeFreeze h'
+        p = percentile h 50
+      lower p `shouldBeLessThanOrEqual` median'
+      upper p `shouldBeGreaterThanOrEqual` median'
diff --git a/test/Data/HdrHistogramSpec.hs b/test/Data/HdrHistogramSpec.hs
new file mode 100644
--- /dev/null
+++ b/test/Data/HdrHistogramSpec.hs
@@ -0,0 +1,32 @@
+{-# LANGUAGE DataKinds           #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+module Data.HdrHistogramSpec where
+
+import           Data.HdrHistogram
+import qualified Data.Vector           as U
+import           Test.Expectations
+import           Test.Hspec
+import           Test.Hspec.QuickCheck (prop)
+import           Test.Utils
+
+type Config' = Config 1 10 1
+
+spec :: Spec
+spec =
+  describe "Histogram" $ do
+    it "should give equal result to reference" $ do
+      let
+        h :: Histogram Config' Int Int
+        h = foldr (flip record) empty [1..10]
+      (upper . (`percentile` 90.0)) h `shouldBe` 9
+
+    prop "should be close to reference implementation" $ \((ConfigAndVals c vals) :: ConfigAndVals c Int) -> do
+      let
+        empty' :: Histogram c Int Int
+        empty' = fromConfig c
+        v = U.fromList vals
+        median' = median v
+        h = U.foldl record empty' v
+        p = percentile h 50
+      lower p `shouldBeLessThanOrEqual` median'
+      upper p `shouldBeGreaterThanOrEqual` median'
diff --git a/test/Spec.hs b/test/Spec.hs
new file mode 100644
--- /dev/null
+++ b/test/Spec.hs
@@ -0,0 +1,1 @@
+{-# OPTIONS_GHC -F -pgmF hspec-discover #-}
diff --git a/test/Test/Expectations.hs b/test/Test/Expectations.hs
new file mode 100644
--- /dev/null
+++ b/test/Test/Expectations.hs
@@ -0,0 +1,29 @@
+module Test.Expectations (
+  shouldBeLessThan,
+  shouldBeLessThanOrEqual,
+  shouldBeGreaterThan,
+  shouldBeGreaterThanOrEqual
+  ) where
+
+import           Control.Monad (unless)
+import           Test.Hspec
+
+expectTrue :: String -> Bool -> Expectation
+expectTrue msg b = unless b (expectationFailure msg)
+
+compareWith :: (Show a) => (a -> a -> Bool) -> String -> a -> a -> Expectation
+compareWith comparator errorDesc result expected = expectTrue errorMsg (comparator expected result)
+  where
+    errorMsg = show result ++ " " ++ errorDesc ++ " " ++ show expected
+
+shouldBeLessThan :: (Show a, Ord a) => a -> a -> Expectation
+shouldBeLessThan = compareWith (>) "is not less than"
+
+shouldBeLessThanOrEqual :: (Show a, Ord a) => a -> a -> Expectation
+shouldBeLessThanOrEqual = compareWith (>=) "is not less than or equal"
+
+shouldBeGreaterThan :: (Show a, Ord a) => a -> a -> Expectation
+shouldBeGreaterThan = compareWith (<) "is not greater than"
+
+shouldBeGreaterThanOrEqual :: (Show a, Ord a) => a -> a -> Expectation
+shouldBeGreaterThanOrEqual = compareWith (<=) "is not greater than or equal"
diff --git a/test/Test/Utils.hs b/test/Test/Utils.hs
new file mode 100644
--- /dev/null
+++ b/test/Test/Utils.hs
@@ -0,0 +1,33 @@
+{-# LANGUAGE ScopedTypeVariables #-}
+module Test.Utils where
+
+import           Control.Monad.ST                  (runST)
+import           Data.Bits                         (Bits)
+import           Data.HdrHistogram.Config.Internal
+import           Data.Tagged                       (Tagged (Tagged))
+import           Data.Vector                       ((!))
+import qualified Data.Vector                       as U
+import           Data.Vector.Algorithms.Intro      (sort)
+import           System.Random                     (Random)
+import           Test.QuickCheck
+
+data ConfigAndVals c a = ConfigAndVals (Tagged c (HistogramConfig a)) [a]
+                    deriving (Show, Eq)
+
+instance (Random a, Arbitrary a, Bounded a, Integral a, Bits a) => Arbitrary (ConfigAndVals c a) where
+  arbitrary = do
+    config' <- arbitrary
+    vals <- listOf1 $ choose (lowest config', highest config')
+    return $ ConfigAndVals (Tagged config') vals
+
+median :: Ord a => U.Vector a -> a
+median s = sorted ! middle
+    where
+     middle = if odd len
+              then len `div` 2
+              else (len `div` 2) - 1
+     sorted = runST $ do
+       v <- U.thaw s
+       sort v
+       U.unsafeFreeze v
+     len = U.length s