RDKit
Open-source cheminformatics and machine learning.
Class List
Here are the classes, structs, unions and interfaces with brief descriptions:
[detail level 1234]
 Nboost
 Nboost_adaptbx
 NChemicalFeatures
 NDistGeom
 NForceFields
 NInvar
 NQueries
 NRankersUtility functionality used to rank sequences
 NRDCatalog
 NRDDataManip
 NRDDepict
 NRDFeatures
 NRDGeom
 NRDInfoTheoryClass used to rank bits based on a specified measure of infomation
 NRDKitStd stuff
 NRDNumeric
 NRDPickers
 CBitVectAbstract base class for storing BitVectors
 CData3Ddescriptors
 CDatastructsException
 CExplicitBitVectClass for bit vectors that are densely occupied
 CIndexErrorExceptionClass to allow us to throw an IndexError from C++ and have it make it back to Python
 CKeyErrorExceptionClass to allow us to throw a KeyError from C++ and have it make it back to Python
 CMolData3Ddescriptors
 CPySequenceHolderClass to hold sequences (lists, tuples, arrays, etc.) passed from Python -> C++
 CSparseBitVectClass for bit vectors that are sparsely occupied
 CValueErrorExceptionClass to allow us to throw a ValueError from C++ and have it make it back to Python