RefDB is a reference database and bibliography tool for SGML, XML, and LaTeX documents, sort of a Reference Manager or BibTeX for markup languages. It is portable and known to run on Linux, Free/NetBSD, OSX, Solaris, and Windows/Cygwin.
The Video Annotation and Reference System (VARS) is a software interface and database system that provides tools for describing, cataloging, retrieving, and viewing the visual, descriptive, and quantitative data associated with video.
Cross-platform open source Redis DB management tool
FastoRedis (fork of FastoNoSQL) — is a cross-platform open source Redis management tool (i.e. Admin GUI). It put the same engine that powers Redis's redis-cli shell. Everything you can write in redis-cli shell — you can write in FastoRedis! Our program works on the most amount of Linux systems, also on Windows, Mac OS X, FreeBSD and Android platforms, on desktops and embedded devices.
MailDB adds a database back-end to an IMAP server for features such as "virtual" mail folders (msgs appearing in multiple folders), "view" folders (dynamic results of searches), etc. The DB is inherently multi-user, allowing msg reference counting.