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.
Xapian is a search engine library, scalable to collections containing hundreds of millions of documents. It's written in C++ with bindings for Perl, Python, PHP, Java, Tcl, C#, Ruby, and Lua. It is a highly adaptable toolkit that allows developers to easily add advanced indexing and search facilities to their own applications. It supports the Probabilistic Information Retrieval model and also a rich set of boolean query operators. Omega is a Web search application built upon the Xapian library. It can index a Web server's document tree (including HTML, PDF, OpenOffice, MS Word/Excel/Powerpoint/Works, WordPerfect, RTF, PS, etc.), or data exported from arbitrary sources (e.g. SQL databases).
Valentina is cross-platform SQL and non-SQL columnar database that allows development of client-server [Web] solutions and applications with an embedded local database using the same sources. Valentina DB provides an Object-Relational model, but you can also mix Relational and Extended Navigational. It introduces a revolutionary model abstraction "Link" that greatly simplifies db schema, and therefore simplifies SQL queries. It supports disk and in-memory databases, and field types including Bit, BLOB, Pictures, and Enum. It provides advanced features such as triggers, views, stored procedures, regular expressions, XML, full-text search, and calculated fields. It exists as Valentina Server, Valentina Studio, and a set of Valentina ADKs for all major programming languages.
OpenSimulator is a multi-platform, multi-user 3D distributed virtual environment platform. Out of the box, it can be used to simulate virtual environments similar to that of Second Life. These can be used as social virtual worlds or for specific applications such as education, training, and visualization. Access is via the regular Second Life open-source viewer or via third-party clients. There are a number of private and public deployments of OpenSimulator, including OSgrid, which has over 8000 regions hosted by independent individuals and organizations spread over the Internet.
DotNetWikiBot Framework is a full-featured client API with a console interface that allows you to build programs and Web robots easily to manage information on MediaWiki-powered sites. DotNetWikiBot Framework is intended to help with many complicated and routine tasks of wiki site development and maintenance. Any .NET language can be used to access DotNetWikiBot library functions. Only minimal programming skills are required to make bots with DotNetWikiBot Framework.
MagicDraw is a visual UML modeling and CASE tool with teamwork support. It is designed for business analysts, software analysts, programmers, QA engineers, and documentation writers. This dynamic and versatile development tool facilitates analysis and design of Object Oriented (OO) systems and databases. It provides a code engineering mechanism (with full round-trip support for J2EE, C#, C++, CORBA IDL programming languages, .NET, XML Schema, WSDL), as well as database schema modeling, DDL generation, and reverse engineering facilities.