PostgreSQL is a robust relational database system with over 25 years of active development that runs on all major operating systems. It is fully ACID compliant, and has full support for foreign keys, joins, views, triggers, and stored procedures (in multiple languages). It includes most SQL92 and SQL99 data types, including INTEGER, NUMERIC, BOOLEAN, CHAR, VARCHAR, DATE, INTERVAL, and TIMESTAMP. It also supports storage of binary large objects, including pictures, sounds, or video. It has native programming interfaces for C/C++, Java, .Net, Perl, Python, Ruby, Tcl, and ODBC, among others, and exceptional documentation.
TUTOS (The Ultimate Team Organization Software) is a groupware, ERP (Enterprise Resource Planing), CRM (Customer Relationship Management), and PLM (Project Lifecycle Management) suite that helps small to medium teams manage various things in one place. Its features include personal and group calendars, an address book, product and project management, bug tracking, installation management, test management, scrum management, a task list, notes, files, mailboxes, and useful links between all of the above.
MUSCLE (Multi User Server Client Linking Environment) is an N-way messaging server and networking API. It includes client-side networking APIs for various languages, including C, C++, C#, Delphi, Java, and Python. MUSCLE lets programs communicate over a network via streams of serialized Message objects. The included server program ("muscled") lets its clients message each other and store information in its server-side hierarchical database. The database supports flexible queries via hierarchical wildcarding, and "live" updates via a subscription mechanism.
TYPO3 CMS is a Web Content Management System which features automatic creation of navigational menus, headlines, and other dynamic graphical elements, automatic conversion and scaling of images, the ability to present different templates based on variables such as client browser or country code, support for multiple templates on a site, and a built-in password-protection option. Pages can be timed to be shown on a certain date, be hidden on a certain date or just temporarily hidden. TYPO3 supports search in SQL-databases and redesigning of a website at once is just a matter of creating a single new template.
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.
Groonga is a fast and accurate full text search engine based on an inverted index. Newly registered document instantly appears in search results, and updates are allowed without read locks. These characteristics result in superior performance for real-time applications. It is also a column-oriented database management system (DBMS). Compared with well-known row-oriented systems, such as MySQL and PostgreSQL, column-oriented systems are more suited for aggregate queries.
db4o is an object database for Java and all .NET environments. Its features include ACID transactions, automatic class schema recognition, query-by-example, a S.O.D.A. object querying API, native queries, LINQ support on .NET, callback methods, memory files, cascade-on-delete, multi-threaded access, and Java Webstart and servlet support.