diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,7 +1,24 @@
-Copyright (c) 2012 Nathan "Taneb" van Doorn
-
-Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the Software), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+Copyright (c) 2012, Nathan "Taneb" van Doorn
+All rights reserved.
 
-The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+    * Neither the name of the <organization> nor the
+      names of its contributors may be used to endorse or promote products
+      derived from this software without specific prior written permission.
 
-THE SOFTWARE IS PROVIDED AS IS, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL NATHAN "TANEB" VAN DOORN BE LIABLE FOR ANY
+DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/family-tree.cabal b/family-tree.cabal
--- a/family-tree.cabal
+++ b/family-tree.cabal
@@ -1,5 +1,5 @@
 name:           family-tree
-version:        0.1
+version:        0.1.1
 cabal-version:  >= 1.2
 build-type:     Simple
 author:         Nathan "Taneb" van Doorn
@@ -12,20 +12,19 @@
                 It also includes appropriate lenses!
 category:       Genealogy, Data
 copyright:      (c) 2012 Nathan "Taneb" van Doorn
-license:        OtherLicense
-license-file:  LICENSE
+license:        BSD3
+license-file:   LICENSE
 
 library
   hs-source-dirs:  src
   build-depends:   
                    base >= 4 && < 5,
-                   text,
-                   containers,
-                   unordered-containers,
-                   bytestring,
-                   time,
-                   data-lens,
-                   binary
+                   text < 0.12,
+                   containers >= 0.4.2 && < 0.6,
+                   unordered-containers < 0.3,
+                   time < 2,
+                   data-lens < 3,
+                   binary < 0.6
   ghc-options:     -Wall
   exposed-modules: Data.FamilyTree
 
diff --git a/src/Data/FamilyTree.hs b/src/Data/FamilyTree.hs
--- a/src/Data/FamilyTree.hs
+++ b/src/Data/FamilyTree.hs
@@ -1,9 +1,4 @@
 {- |
-Module      :  $Header$
-Description :  Family trees with lenses
-Copyright   :  (c) 2012 Nathan "Taneb" van Doorn
-License     :  MIT License
-
 Maintainer  :  nvd124@gmail.com
 Stability   :  unstable
 Portability :  portable
@@ -14,24 +9,44 @@
 
 Better description coming soon!
 -}
-module Data.FamilyTree where
+module Data.FamilyTree
+ (Person(..)
+ ,Family(..)
+ ,Event(..)
+ ,Location(..)
+ ,Relationship(..)
+ ,FamilyTree(..)
+ ,ID
+ ,newTree
+ ,personLens
+ ,familyLens
+ ,eventLens
+ ,addPerson
+ ,addFamily
+ ,addEvent
+ ,deletePerson
+ ,deleteFamily
+ ,deleteEvent
+) where
 
+import Control.Applicative
 import Control.Arrow
 import Control.Monad
 
 import Data.Binary
 import Data.Function
-import Data.HashMap.Lazy (HashMap)
-import qualified Data.HashMap.Lazy as HM
+import Data.HashMap.Strict (HashMap)
+import qualified Data.HashMap.Strict as HM
 import Data.Lens.Common
+import Data.Maybe
 import Data.IntMap (IntMap)
 import qualified Data.IntMap as IM
 import Data.IntSet (IntSet)
 import qualified Data.IntSet as IS
 import Data.Text (Text)
-import qualified Data.Text as T 
+import qualified Data.Text as T
 import Data.Text.Encoding
-import Data.Time
+import Data.Time (Day(..))
 
 data Person = Person
   {name :: Maybe Text
@@ -84,7 +99,7 @@
         x <- get
         y <- get
         return $ Coord x y
-      1 -> fmap (PlaceName . decodeUtf8) get
+      _ -> PlaceName . decodeUtf8 <$> get
 
 instance Binary Relationship where
   put (Other t) = do
@@ -94,15 +109,15 @@
   get = do
     tag <- getWord8
     case tag of
-      0 -> fmap (Other . decodeUtf8) get
-      1 -> return Marriage
+      0 -> Other . decodeUtf8 <$> get
+      _ -> return Marriage
 
 instance Binary Person where
   put person = do
-    put (fmap encodeUtf8 $ name person)
-    put (fmap toModifiedJulianDay $ birthdate person)
+    put (encodeUtf8 <$> name person)
+    put (toModifiedJulianDay <$> birthdate person)
     put (birthplace person)
-    put (fmap toModifiedJulianDay $ deathdate person)
+    put (toModifiedJulianDay <$> deathdate person)
     put (deathplace person)
     put (map (join (***) encodeUtf8) . HM.toList $ attributes person)
     put (attendedEvents person)
@@ -129,8 +144,8 @@
     put $ head1 fam
     put $ head2 fam
     put $ relationship fam
-    put $ fmap toModifiedJulianDay $ relationFrom fam
-    put $ fmap toModifiedJulianDay $ relationTo fam
+    put $ toModifiedJulianDay <$> relationFrom fam
+    put $ toModifiedJulianDay <$> relationTo fam
     put $ children fam
   get = do
     h1 <- get
@@ -151,7 +166,7 @@
 instance Binary Event where
   put evnt = do
     put . encodeUtf8 $ eventInfo evnt
-    put $ fmap toModifiedJulianDay $ eventDate evnt
+    put $ toModifiedJulianDay <$> eventDate evnt
     put $ eventAttendees evnt
   get = do
     n <- get
@@ -181,8 +196,10 @@
       ,events = e
       }
 
-personLens :: Int -> Lens FamilyTree Person
-personLens n = lens ((IM.! n) . people) $
+newtype ID = ID Int
+
+personLens :: ID -> Lens FamilyTree Person
+personLens (ID n) = lens ((IM.! n) . people) $
   \person familyTree ->
     let oldPerson = people familyTree IM.! n
         newattended = (IS.difference `on` attendedEvents)
@@ -200,15 +217,15 @@
           (events familyTree) newattended) oldattended
       }
       
-familyLens :: Int -> Lens FamilyTree Family
-familyLens n = lens ((IM.! n) . families) $
+familyLens :: ID -> Lens FamilyTree Family
+familyLens (ID n) = lens ((IM.! n) . families) $
   \family' familyTree ->
     familyTree
       {families = IM.insert n family' (families familyTree)
       }
       
-eventLens :: Int -> Lens FamilyTree Event
-eventLens n = lens ((IM.! n) . events) $
+eventLens :: ID -> Lens FamilyTree Event
+eventLens (ID n) = lens ((IM.! n) . events) $
   \event familyTree ->
     familyTree
       {events = IM.insert n event (events familyTree)
@@ -258,28 +275,34 @@
   ,eventAttendees = IS.empty
   }
   
-addPerson :: FamilyTree -> (FamilyTree, Int)
+addPerson :: FamilyTree -> (FamilyTree, ID)
 addPerson familyTree =
-  let ((n,_):_) = dropWhile (uncurry (==)) $
-                    zip [1..] $ IM.keys $ people familyTree
+  let n = maybe 0 fst $
+          listToMaybe $
+          dropWhile (uncurry (==)) $
+          zip [1 ..] $ IM.keys $ people familyTree
   in (familyTree
-       {people = IM.insert n blankPerson $ people familyTree}, n)
+       {people = IM.insert n blankPerson $ people familyTree}, ID n)
   
-addFamily :: FamilyTree -> (FamilyTree, Int)
+addFamily :: FamilyTree -> (FamilyTree, ID)
 addFamily familyTree =
-  let ((n,_):_) = dropWhile (uncurry (==)) $
-                    zip [1..] $ IM.keys $ families familyTree
+  let n = maybe 0 fst $
+          listToMaybe $
+          dropWhile (uncurry (==)) $
+          zip [1 ..] $ IM.keys $ families familyTree
   in (familyTree 
-       {families = IM.insert n blankFamily $ families familyTree}, n)
+       {families = IM.insert n blankFamily $ families familyTree}, ID n)
 
-addEvent :: FamilyTree -> (FamilyTree, Int)
+addEvent :: FamilyTree -> (FamilyTree, ID)
 addEvent familyTree =
-  let ((n,_):_) = dropWhile (uncurry (==)) $
-                    zip [1..] $ IM.keys $ events familyTree
-  in (familyTree {events = IM.insert n blankEvent $ events familyTree}, n)
+  let n = maybe 0 fst $
+          listToMaybe $
+          dropWhile (uncurry (==)) $
+          zip [1 ..] $ IM.keys $ events familyTree
+  in (familyTree {events = IM.insert n blankEvent $ events familyTree}, ID n)
   
-deletePerson :: Int -> FamilyTree -> FamilyTree
-deletePerson n familyTree =
+deletePerson :: ID -> FamilyTree -> FamilyTree
+deletePerson (ID n) familyTree =
   familyTree 
     {people = IM.delete n $ people familyTree
     ,families = IM.map
@@ -297,13 +320,13 @@
       (events familyTree)
     }
     
-deleteFamily :: Int -> FamilyTree -> FamilyTree
-deleteFamily n familyTree =
+deleteFamily :: ID -> FamilyTree -> FamilyTree
+deleteFamily (ID n) familyTree =
   familyTree
     {families = IM.delete n $ families familyTree}
 
-deleteEvent :: Int -> FamilyTree -> FamilyTree
-deleteEvent n familyTree =
+deleteEvent :: ID -> FamilyTree -> FamilyTree
+deleteEvent (ID n) familyTree =
   let relevantPeople = eventAttendees (events familyTree IM.! n)
   in familyTree
        {events = IM.delete n $ events familyTree
@@ -311,3 +334,11 @@
          (\p -> p {attendedEvents = IS.delete n $ attendedEvents p}))
          (people familyTree) relevantPeople
        }           
+       
+newTree :: Text -> FamilyTree
+newTree n = FamilyTree
+  {treeName = n
+  ,people = IM.empty
+  ,families = IM.empty
+  ,events = IM.empty
+  }