SQLite is a small, fast, embeddable SQL database engine that supports most of SQL92, including transactions with atomic commit and rollback, subqueries, compound queries, triggers, and views. A complete database is stored in a single cross-platform disk file. The native C/C++ API is simple and easy to use. Bindings for other languages are also available.
The NCBI C++ Toolkit provides portable libraries and applications for assisting genetic science. These include libraries for networking, SQL and BerkeleyDB access, CGI and HTML handling, ASN.1 and XML handling, sequence alignment engines, sequence retrieval engines, BLAST database engines, FLTK and OpenGL graphics toolkits, and basic system utilities.
Flora is a minimalistic but very powerful NoSQL database. It is easy to understand with data readable by both humans and machines, schemaless, Lua-scriptable, remotely accessible through TCP, and portable. It is especially suited for A. I. tasks, and a longer-term goal is support for "natural language" queries.