PloobsEngine is an opensource engine for creating games and graphics applications developed in XNA 4.0, C# .Net 4.0 and HLSL. It is designed to be simple and easy to use even for those unfamiliar with computer graphics programming.
Ploobs Frequently Asked Questions (English)
Release in Portuguese: http://www.bitabit.eng.br/2011/03/23/apresentando-ploobs-engine/
Usando e Contribuindo com a PloobsEngine (Portugues)
Old Project site (XNA 3.1 Version): http://ploobsengine.codeplex.com/