eXist-db is an open source database management system that stores XML data according to the XML data model and features efficient, index-based XQuery processing.

"Heurist captures and manages web bookmarks, bibliographic references, personal notes and a host of other specialised data types (expandable) in a simple, searchable web interface, available anywhere.

Researchers can easily and quickly find, capture and share relevant information, organise information resources and publish teaching/research project web site content automatically using Heurist."

Navicat for MySQL is an interface for working with MySQL databases, including importing data from CSV or Excel, exporting, reporting, querying, etc.

PostgreSQL is a powerful, open source object-relational database system running on all major platforms. Support for native programming interfaces for C/C++, Java, .Net, Perl, Python, Ruby, Tcl and ODBC among others.
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Project Quincy allows users to trace the development of social networks and institutions over time and space using information about people, places and organizations. It is a Ruby on Rails application with a MySQL database that can be installed on a web server.