Firebird RDBMS offers ANSI SQL features & runs on Linux, Windows & several Unix platforms. Features excellent concurrency & performance & powerful stored procedure & trigger language.
More information and downloads at https://firebirdsql.org/, issue tracker is https://github.com/FirebirdSQL/firebird/issues
Cloud Target is a front-end to the python scripts that google uses to create, run and upload projects to its App Server system. This .NET application is based on the OSX front-end provided by Google in the SDK.
XSDB XML is to DATA as HTML is to DOCUMENT. Publish and combine data as easily as HTML format and web browsers publish and view documents. Implementations in Python, javascript, java, C#/.NET.
COMBuilder is a VB6 app that will allow you to write all COM objects for working with databases. Also, the program will create forms to work with this objects. It is planned to create also c# and vb.net code.