PostSharp is a post-compiler for the .NET Framework. It contains not only an MSIL reader/writer but also a low-level code weaver on which weavers of higher level can be built with relative ease. It is designed as a platform that integrates seamlessly in the MSBuild process.
This is the third and the last Alpha release of PostSharp 1.0. It comes with PostSharp Laos [Light Aspect-Oriented System], that enables developing aspects just by inheriting some custom attributes. The release comes with samples so you can get started really quickly.
Most of APIes are now nearly final. Please refer to the PostSharp Roadmap for planned modifications. This Alpha release is a mature version with good stability and is reliable for depending developments.