InfiniSQL is a distributed in-memory NewSQL relational database management system (RDBMS). It excels at performing complex transactions which involve records on multiple server nodes. It is engineered around the actor model of concurrent programming, which enables unique scalability capabilities.
RecDB is a recommendation engine built entirely inside PostgreSQL 9.2. It allows application developers to build recommendation applications using a wide variety of built-in recommendation algorithms such as user-user collaborative filtering, item-item collaborative filtering, and singular value decomposition. Applications powered by RecDB can produce online and flexible personalized recommendations to end-users. It is easily used and configured and allows novice developers to define a variety of recommenders that fits their application's needs in few lines of SQL. It can seamlessly integrate recommendation functionality with traditional database operations.
EJDB is an embedded JSON database engine. It aims to be a fast MongoDB-like NoSQL library that can be embedded into C/C++/Nodejs/Python3/Lua applications. It features collection-level write locking, collection level transactions, string token matching queries, and a Node.js binding.
The psycogreen package makes it possible for psycopg2 to work with coroutine libraries, using asynchronous calls internally but offering a blocking interface so that regular code can run unmodified. While Psycopg offers coroutine support, the main module is a C extension that cannot be monkey-patched to become coroutine-friendly. Instead it exposes a hook that coroutine libraries can use to install a function integrating with their event scheduler. Psycopg will call the function whenever it executes a libpq call that may block. psycogreen is a collection of "wait callbacks" that can be used to integrate Psycopg with different coroutine libraries. psycogreen is currently mainly useful for integration with gevent.
Barman (backup and recovery manager) for PostgreSQL is an administration tool for disaster recovery of PostgreSQL servers. It allows remote backups of multiple servers in business-critical environments and helps DBAs during the recovery phase. Barman's most-wanted features include backup catalogs, retention policies, remote recovery, archiving, and compression of WAL files and backups.
pg-python provides access to Python from PostgreSQL. It contrasts with the built-in procedural language by interfacing with PostgreSQL types rather than converting them. This allows large instances of data types to be handled with greater efficiency while also allowing reasonable support for arbitrary data types without the need for a specialized implementation. Procedures are managed as entire modules so that initialization can be performed naturally by a stored procedure (each PostgreSQL function has a "main" entry point). Import statements may exist in a more natural position, and the "main" entry point may be decorated.
FreeTable is a cloud database service that allows programmers to upload and download individual data values using a SQL-like API. Language bindings exist for Python, PHP, and Ruby. In many respects FreeTable is a data wiki, with notions of revision history, curation, and data rollback/roll forward.