diff --git a/src/Lsystem/Generator.hs b/src/Lsystem/Generator.hs
index 0819f0d..79acff4 100644
--- a/src/Lsystem/Generator.hs
+++ b/src/Lsystem/Generator.hs
@@ -1,3 +1,12 @@
+{-|
+Module      : Lsystem.Generator
+Description : Generate the L-system
+Copyright   : (c) Zebulun Arendsee, 2018
+License     : MIT
+Maintainer  : zbwrnz@gmail.com
+Stability   : experimental
+-}
+
 module Lsystem.Generator
 (
     step
@@ -40,9 +49,9 @@ applyRules g lc rc rs n = fromMaybe [n] . firstSuccess (applyRule p) $ rs
     applyRule :: Chance -> Rule -> Maybe [Node]
     applyRule _ (DeterministicRule cont cond match repl) =
       return (repl lc rc n) -- replace node if:
-        >>= match n         -- * the node is of the correct form
-        >>= cont lc rc      -- * it is in the required context
-        >>= cond lc rc n    -- * all parametric restrictions are met
+        >>= match n         --   the node is of the correct form
+        >>= cont lc rc      --   it is in the required context
+        >>= cond lc rc n    --   all parametric restrictions are met
     applyRule p (StochasticRule rs') = case (choose p rs') of
       -- p is rescaled by dividing by the selected rule's probability
       Just (cp', r) -> applyRule (p / cp') r
diff --git a/src/Lsystem/Grammar.hs b/src/Lsystem/Grammar.hs
index 257624e..e7fd856 100644
--- a/src/Lsystem/Grammar.hs
+++ b/src/Lsystem/Grammar.hs
@@ -1,3 +1,12 @@
+{-|
+Module      : Lsystem.Grammar
+Description : Core types
+Copyright   : (c) Zebulun Arendsee, 2018
+License     : MIT
+Maintainer  : zbwrnz@gmail.com
+Stability   : experimental
+-}
+
 module Lsystem.Grammar
 (
     System(..)
@@ -13,17 +22,17 @@ module Lsystem.Grammar
   , Chance
 ) where
 
--- context-sensitive stochastic parameterized L-systems
+-- 
 
-type Distance = Double -- x > 0
-type Yaw      = Double -- -180 < x < 180
-type Pitch    = Double -- -180 < x < 180
-type Roll     = Double -- -180 < x < 180
+type Distance = Double -- ^ x > 0
+type Yaw      = Double -- ^ -180 < x < 180
+type Pitch    = Double -- ^ -180 < x < 180
+type Roll     = Double -- ^ -180 < x < 180
 
 type LeftContext  = [Node]
 type RightContext = [Node]
 
-type Chance = Double -- 0 <= x <= 1
+type Chance = Double -- ^ 0 <= x <= 1
 
 data System = System {
       systemBasis :: [Node]
diff --git a/src/Lsystem/Render.hs b/src/Lsystem/Render.hs
index d0ed6ae..a05bcb9 100644
--- a/src/Lsystem/Render.hs
+++ b/src/Lsystem/Render.hs
@@ -2,6 +2,15 @@
 {-# LANGUAGE FlexibleContexts          #-}
 {-# LANGUAGE TypeFamilies              #-}
 
+{-|
+Module      : Lsystem.Render
+Description : Render a generated L-system
+Copyright   : (c) Zebulun Arendsee, 2018
+License     : MIT
+Maintainer  : zbwrnz@gmail.com
+Stability   : experimental
+-}
+
 module Lsystem.Render
 (
   renderSystem
diff --git a/src/Lsystem/Sugar.hs b/src/Lsystem/Sugar.hs
index 6eaf91c..2fd690a 100644
--- a/src/Lsystem/Sugar.hs
+++ b/src/Lsystem/Sugar.hs
@@ -1,3 +1,12 @@
+{-|
+Module      : Lsystem.Sugar
+Description : Functions for simplifying L-system specification
+Copyright   : (c) Zebulun Arendsee, 2018
+License     : MIT
+Maintainer  : zbwrnz@gmail.com
+Stability   : experimental
+-}
+
 module Lsystem.Sugar
 (
     transDol
@@ -68,11 +77,11 @@ matchWidth _ _ = Nothing
 unconditional :: LeftContext -> RightContext -> Node -> a -> Maybe a
 unconditional _ _ _ x = Just x
 
--- Check is A is a similar to B. For branches, A must be a subtree of B.
+-- | Check is A is a similar to B. For branches, A must be a subtree of B.
 similar
-  :: Node -- A
-  -> Node -- B
-  -> Bool -- True is A is in B (where `in` is weirdly defined ...)
+  :: Node -- ^ A
+  -> Node -- ^ B
+  -> Bool -- ^ True if A is in B (where `in` is weirdly defined ...)
 similar (NodeDummy _ s) (NodeDummy _ t) = s == t
 similar (NodeDraw _ _ ) (NodeDraw _ _) = True
 similar (NodeRotate _ _ _ _) (NodeRotate _ _ _ _) = True
@@ -92,11 +101,11 @@ similar (NodeBranch mss) (NodeBranch nss) = any id $ map (anyBranch nss) mss
 similar _ _ = False
 
 contextMatch
-  :: [Node] -- elements to ignore
-  -> [Node] -- left contextual pattern
-  -> [Node] -- right contextual pattern
-  -> [Node] -- left context
-  -> [Node] -- right context
+  :: [Node] -- ^ elements to ignore
+  -> [Node] -- ^ left contextual pattern
+  -> [Node] -- ^ right contextual pattern
+  -> [Node] -- ^ left context
+  -> [Node] -- ^ right context
   -> a -> Maybe a -- combinator kludge (I really should go to Bool)
 contextMatch ss lpat rpat lc rc x =
   return x