Python bsddb3 is a Python module that provides a nearly complete wrapping of the Oracle/Sleepycat C API for the database environment, database, cursor, sequence, and transaction objects, and each of these is exposed as a Python type in the bsddb3.db module. The database objects can use various access methods: btree, hash, recno, and queue. It has complete support for Berkeley DB distributed transactions, and complete support for the Berkeley DB Replication Manager and base replication API. The goal is to mirror most of the real Berkeley DB API.
SQLObject is an object-relational mapper, i.e., a library that will wrap your database tables in Python classes and your rows in Python instances. It currently supports MySQL through the 'MySQLdb' package, PostgreSQL through the 'psycopg' package, SQLite, Firebird, MaxDB (SAP DB), MS SQL, and Sybase. It should support Python versions back to 2.4.
The Maximum Entropy Toolkit provides a set of tools and library for constructing maximum entropy (maxent) models in either Python or C++. It features conditional maximum entropy models, L-BFGS and GIS parameter estimation, Gaussian Prior smoothing, a C++ API, a Python extension module, a command line utility, and good documentation.
The Darwin Calendar Server is a standards-compliant server that allows multiple users to collaboratively share calendaring information. It provides a shared location on the network to store schedules, and allows users to send each other and manage invitations. In order to provide interoperability with multiple calendaring clients, the server implements the CalDAV protocol, which is an extension of WebDAV, which is in turn an extension of HTTP.