SharePoint 2007
Present since the first betas as a developper and previously admin on 2003 and older CMS version, the know how and the expertise on this platform is very large and covers now almost every aspect of this product. Now working on the new version with a great interest but not enough time to really dig in, my current projects are still 2007.
Free Tools or Webparts :
Tracing Delegate Control.
jQuery integration.
Ajax integration.
XslRenderingWebpart.
Easy Styling Kit.
Easy Stripping Kit.
Another CAML Query Builder.
LinqToSharePoint Rewrite.
Research and discoveries in SharePoint Wonderland.
SharePoint Query Objects and Performance.
Sparing SPWeb and SPSite using the request.