Hi, I've added the code for the database project to the sandbox. I've also made the following changes based on feedback from Caleb and Jonathan: 1) fixed <: digraphs 2) added transaction functions to the abstract interface. Added a reference_counted_transaction_manager class for use in implementations that don't support nested transactions. 3) made the interface support null field detection via boost.optional 4) iteration supports BiDirectional model instead of RandomAccess 5) added a transaction class for scoped transaction management on the to-do list: 1) documentation - this is going to be a word document or something at first since I know nothing about html. 2) make .jam files 3) test cases - I'm not sure how these are going to work. 4) investigate possibility of supporting a prepare_statement function