Its most exiting feature: it is twice faster than PostSharp 1.0! PostSharp 1.5 CTP 3 includes all bug fixes of PostSharp 1.0 SP1. Except performance, this release does not bring any new feature, but went through some refactoring to solve design problems of CTP 2, and documents new features.
For those who still use 1.0, here is a summary of new features of 1.5:
Reading assemblies without loading them in the CLR
In version 1.0, PostSharp required assemblies to be loaded in the CLR (i.e. in the application domain) to be able to read them. This limitation belongs to the past. When PostSharp processes a Silverlight or a Compact Framework assembly, it is never loaded by the CLR.
Lazy loading of assemblies
When PostSharp has to load a dependency assembly, it now reads only the metadata objects it really needs, resulting in a huge performance improvement and much lower memory consumption.
The code has been carefully profiled and optimized for maximal performance.
Support for Novell Mono
PostSharp is now truly cross-platform. Binaries compiled on the Microsoft platform can be executed under Novell Mono. Both Windows and Linux are tested and supported. A NAnt task makes it easier to use PostSharp in these environments.
Support for Silverlight 2.0 and the Compact Framework
You can add aspects to your projects targeting Silverlight 2.0 or the Compact Framework 2.0.
Pluggable Aspect Serializer & Partial Trust
Previously, all aspects were serializer using the standard .NET binary formatter. It is now possible to choose another serializer or implement your own, and enhance assemblies that be executed with partial trust.
The next release will be a release candidate; expect it in 1-2 months according to the pace of bug reports.