Do you like code and custom solutions, then you should get to know CodePlex, the Open Source Project Community. With over 115 project you can sort by:
CodePlex is Microsoft's open source project hosting web site. You can use CodePlex to create new projects to share with the world, join others who have already started their own projects, or use the applications on this site and provide feedback.
To view all the CRM code projects available today use this link: http://www.codeplex.com/site/search?projectSearchText=crm