Open Source SharePoint Project

Question

Goal:
Learn real-based SharePoint project based on customization with Visual Studio. I wanna learn the source code, architecture, N-tier etc of a completed SP project.

Problem:
Is there one or many open source SP project that can be downloaded for free?

Information:
- I'm using SharePoint 2013, Visual Studio 2012 and SQL server 2012

Answer 1

On the Microsoft site for sharing code samples, located at http://code.msdn.microsoft.com/ I found 144 solutions tagged SharePoint Server 2013, which I belive will keep you occupied over the weekend :-)