diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,7 @@
+2021-03-07
+        * Version bump (3.2.1). (#46)
+        * Completed the documentation. (#42)
+
 2020-12-06
         * Version bump (3.2).
         * Implemented arrays in test driver (#37).
diff --git a/copilot-c99.cabal b/copilot-c99.cabal
--- a/copilot-c99.cabal
+++ b/copilot-c99.cabal
@@ -1,6 +1,6 @@
 cabal-version             : >= 1.10
 name                      : copilot-c99
-version                   : 3.2
+version                   : 3.2.1
 synopsis                  : A compiler for Copilot targeting C99.
 description               :
   This package is a back-end from Copilot to C.
@@ -41,7 +41,7 @@
                           , mtl                 >= 2.2 && < 2.3
                           , pretty              >= 1.1 && < 1.2
 
-                          , copilot-core        >= 3.2   && < 3.3
+                          , copilot-core        >= 3.2.1 && < 3.3
                           , language-c99        >= 0.1.1 && < 0.2
                           , language-c99-util   >= 0.1.1 && < 0.2
                           , language-c99-simple >= 0.1.1 && < 0.2
@@ -64,8 +64,8 @@
                   , Copilot.Compile.C99.Property.SequencePoint
   build-depends:    base
                   , copilot-core
-                  , copilot-c99         >= 3.2 && < 3.3
-                  , copilot-language    >= 3.2 && < 3.3
+                  , copilot-c99         >= 3.2.1 && < 3.3
+                  , copilot-language    >= 3.2.1 && < 3.3
                   , language-c99        >= 0.1.2 && < 0.2
                   , language-c99-simple
                   , pretty              >= 1.1.3 && < 1.2
diff --git a/src/Copilot/Compile/C99.hs b/src/Copilot/Compile/C99.hs
--- a/src/Copilot/Compile/C99.hs
+++ b/src/Copilot/Compile/C99.hs
@@ -1,3 +1,4 @@
+-- | Compile Copilot specifications to C99 code.
 module Copilot.Compile.C99
   ( compile
   ) where
diff --git a/src/Copilot/Compile/C99/CodeGen.hs b/src/Copilot/Compile/C99/CodeGen.hs
--- a/src/Copilot/Compile/C99/CodeGen.hs
+++ b/src/Copilot/Compile/C99/CodeGen.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 
+-- | High-level translation of Copilot Core into C99.
 module Copilot.Compile.C99.CodeGen where
 
 import Control.Monad.State  (runState)
@@ -25,7 +26,7 @@
   cty = C.decay $ transtype ty
   (cexpr, (cvars, _)) = runState (transexpr expr) mempty
 
--- | Make a extern declaration of an variable.
+-- | Make a extern declaration of a variable.
 mkextdecln :: External -> C.Decln
 mkextdecln (External name _ ty) = decln where
   decln = C.VarDecln (Just C.Extern) cty name Nothing
@@ -52,7 +53,7 @@
   cty     = C.TypeSpec $ C.TypedefName "size_t"
   initval = Just $ C.InitExpr $ C.LitInt 0
 
--- | The step function updates all streams,a
+-- | Writes the step function, that updates all streams.
 mkstep :: [Stream] -> [Trigger] -> [External] -> C.FunDef
 mkstep streams triggers exts = C.FunDef void "step" [] declns stmts where
   void = C.TypeSpec C.Void
@@ -126,7 +127,7 @@
   mkfield :: Value a -> C.FieldDecln
   mkfield (Value ty field) = C.FieldDecln (transtype ty) (fieldname field)
 
--- | Write a forward struct decralration.
+-- | Write a forward struct declaration.
 mkstructforwdecln :: Struct a => Type a -> C.Decln
 mkstructforwdecln (Struct x) = C.TypeDecln struct where
   struct = C.TypeSpec $ C.Struct (typename x)
@@ -145,7 +146,7 @@
   Op3 _ e1 e2 e3        -> exprtypes e1 `union` exprtypes e2 `union` exprtypes e3
   Label ty _ _          -> typetypes ty
 
--- | List all types of an type, returns items uniquely.
+-- | List all types of a type, returns items uniquely.
 typetypes :: Typeable a => Type a -> [UType]
 typetypes ty = case ty of
   Array ty' -> [UType ty] `union` typetypes ty'
diff --git a/src/Copilot/Compile/C99/Compile.hs b/src/Copilot/Compile/C99/Compile.hs
--- a/src/Copilot/Compile/C99/Compile.hs
+++ b/src/Copilot/Compile/C99/Compile.hs
@@ -1,3 +1,4 @@
+-- | Compile Copilot specifications to C99 code.
 module Copilot.Compile.C99.Compile
   ( compile
   ) where
@@ -15,7 +16,9 @@
 import Copilot.Compile.C99.Translate
 import Copilot.Compile.C99.CodeGen
 
--- | Compile the specification to a .h and a .c file.
+-- | Compile a specification to a .h and a .c file.
+--
+-- The first argument is used as prefix for the .h and .c files generated.
 compile :: String -> Spec -> IO ()
 compile prefix spec = do
   let cfile = render $ pretty $ C.translate $ compilec spec
@@ -37,12 +40,14 @@
   writeFile (prefix ++ ".c") $ cmacros ++ cfile
   writeFile (prefix ++ ".h") hfile
 
--- | Generate the .c file from a spec. It has the following structure:
--- |
--- | * Include .h file
--- | * Declarations of global buffers and indices.
--- | * Generator functions for streams, guards and trigger args.
--- | * Declaration of step() function.
+-- | Generate the .c file from a 'Spec'.
+--
+-- The generated C file has the following structure:
+--
+-- * Include .h file.
+-- * Declarations of global buffers and indices.
+-- * Generator functions for streams, guards and trigger arguments.
+-- * Declaration of the @step()@ function.
 compilec :: Spec -> C.TransUnit
 compilec spec = C.TransUnit declns funs where
   streams  = specStreams spec
@@ -87,7 +92,7 @@
       arggen :: (String, UExpr) -> C.FunDef
       arggen (argname, UExpr ty expr) = genfun argname expr ty
 
--- | Generate the .h file from a spec.
+-- | Generate the .h file from a 'Spec'.
 compileh :: Spec -> C.TransUnit
 compileh spec = C.TransUnit declns [] where
   streams  = specStreams spec
diff --git a/src/Copilot/Compile/C99/External.hs b/src/Copilot/Compile/C99/External.hs
--- a/src/Copilot/Compile/C99/External.hs
+++ b/src/Copilot/Compile/C99/External.hs
@@ -1,5 +1,7 @@
 {-# LANGUAGE ExistentialQuantification #-}
 
+-- | Represent information about externs needed in the generation of C99 code
+-- for stream declarations and triggers.
 module Copilot.Compile.C99.External where
 
 import Data.List  (unionBy)
@@ -14,11 +16,15 @@
   , exttype    :: Type a
   }
 
--- | Union over lists of External, we solely base the equality on the extname's.
+-- | Union over lists of External, we solely base the equality on the
+-- extname's.
 extunion :: [External] -> [External] -> [External]
 extunion = unionBy (\a b -> extname a == extname b)
 
 -- | Collect all external variables from the streams and triggers.
+--
+-- Although Copilot specifications can contain also properties and theorems,
+-- the C99 backend currently only generates code for streams and triggers.
 gatherexts :: [Stream] -> [Trigger] -> [External]
 gatherexts streams triggers = streamsexts `extunion` triggersexts where
   streamsexts  = foldr extunion mempty $ map streamexts streams
diff --git a/src/Copilot/Compile/C99/Translate.hs b/src/Copilot/Compile/C99/Translate.hs
--- a/src/Copilot/Compile/C99/Translate.hs
+++ b/src/Copilot/Compile/C99/Translate.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE GADTs #-}
 
+-- | Translate Copilot Core expressions and operators to C99.
 module Copilot.Compile.C99.Translate where
 
 import Control.Monad.State
@@ -9,7 +10,7 @@
 
 import qualified Language.C99.Simple as C
 
--- | Translates a Copilot expression into a C99 expression.
+-- | Translates a Copilot Core expression into a C99 expression.
 transexpr :: Expr a -> State FunEnv C.Expr
 transexpr (Const ty x) = return $ constty ty x
 
@@ -51,7 +52,8 @@
   return $ transop3 op e1' e2' e3'
 
 
--- | Translates a Copilot unary operator and arguments into a C99 expression.
+-- | Translates a Copilot unary operator and its argument into a C99
+-- expression.
 transop1 :: Op1 a b -> C.Expr -> C.Expr
 transop1 op e = case op of
   Not             -> (C..!) e
@@ -77,7 +79,8 @@
   Cast     _ ty  -> C.Cast (transtypename ty) e
   GetField (Struct _)  _ f -> C.Dot e (accessorname f)
 
--- | Translates a Copilot binary operator and arguments into a C99 expression.
+-- | Translates a Copilot binary operator and its arguments into a C99
+-- expression.
 transop2 :: Op2 a b c -> C.Expr -> C.Expr -> C.Expr
 transop2 op e1 e2 = case op of
   And          -> e1 C..&& e2
@@ -103,12 +106,14 @@
   BwShiftR _ _ -> e1 C..>> e2
   Index    _   -> C.Index e1 e2
 
--- | Translates a Copilot ternaty operator and arguments into a C99 expression.
+-- | Translates a Copilot ternary operator and its arguments into a C99
+-- expression.
 transop3 :: Op3 a b c d -> C.Expr -> C.Expr -> C.Expr -> C.Expr
 transop3 op e1 e2 e3 = case op of
   Mux _ -> C.Cond e1 e2 e3
 
--- | Give a C99 literal expression based on a value and a type.
+-- | Transform a Copilot Core literal, based on its value and type, into a C99
+-- literal.
 constty :: Type a -> a -> C.Expr
 constty ty = case ty of
   Bool   -> C.LitBool
@@ -135,6 +140,7 @@
         _         -> map (C.InitExpr . constty ty) xs
 
 
+-- | Explicitly cast a C99 value to a type.
 explicitty :: Type a -> C.Expr -> C.Expr
 explicitty ty = C.Cast (transtypename ty)
 
diff --git a/src/Copilot/Compile/C99/Util.hs b/src/Copilot/Compile/C99/Util.hs
--- a/src/Copilot/Compile/C99/Util.hs
+++ b/src/Copilot/Compile/C99/Util.hs
@@ -1,3 +1,4 @@
+-- | Auxiliary helper functions to generate C99 code.
 module Copilot.Compile.C99.Util where
 
 import Control.Monad.State
@@ -5,7 +6,9 @@
 import Copilot.Core  (Id)
 import qualified Language.C99.Simple.AST as C
 
-
+-- | Auxiliary type used to collect all the declarations of all the variables
+-- used in a function to be generated, since variable declarations are always
+-- listed first at the top of the function body.
 type FunEnv = ([C.Decln], [C.Ident])
 
 -- | `tell` equivalent for `State`.
@@ -38,7 +41,7 @@
 generatorname :: Id -> String
 generatorname sid = streamname sid ++ "_gen"
 
--- | Turn a the name of a trigger into a guard generator.
+-- | Turn the name of a trigger into a guard generator.
 guardname :: String -> String
 guardname name = name ++ "_guard"
 
@@ -50,5 +53,6 @@
 argnames :: String -> [String]
 argnames base = [aname | n <- [0..], let aname = argname base n]
 
+-- | Define a C expression that calls a function with arguments.
 funcall :: C.Ident -> [C.Expr] -> C.Expr
 funcall name args = C.Funcall (C.Ident name) args