* Why are there only 3 projects? For example the "DataRowExtensions" is in same project as "BitmapExtensions". If someone want use some extension methods and don't use some assembly (System.Data or System.Drawing, etc...), they must extract
the methods from the original project and create they own branch.
It's a decision based on our own use. Most developers decide by application type (eg. Class Library, Windows Forms, WPF, ASP.NET, ...). Those methods that are dedicated to a specific type of application got a separate project. The other "core"
is placed in the core assembly. For me it does not make much sense to have a bulk of assemblies just to prevent a FCL core assembly to be referenced which is anyway available on every single box (eg. System.Data, System.Xml, ...).
* Why are not used namespaces in the projects?
To allow developers to just reference the assemblies and to use the extensions without the need to additionally import any namespaces.
* Are somewhere available test projects of the extension methods?
No, but as mentioned on the site, I'm interested to add them.
* Are you intersted in new contributors and new areas of extension methods such as winforms, threading, etc...?
Yes. I very interested to see the library growing, so feel free to add yourself to the project team and to contribute additional methods and / or tests.