PostSharp
- Post-compiler for .NET; platform for analyzing or transforming .NET assemblies after compiling. One main use is Aspect-Oriented Programming, AOP/AOSD. allosw developing custom attributes that change the behavior of code. Open source.
- http://www.postsharp.org/

AspectR
- Module adding simple aspect-oriented programming concepts to Ruby. Provides join points, advice, aspects, regexps, and pointcut parameters. [Open Source, LGPL]
- http://aspectr.sourceforge.net/

TransWarp
- A general purpose Aspect-Oriented Programming, Generative Programming, and CASE toolkit for Python. [Open Source, BSD-like]
- http://www.zope.org/Members/pje/Wikis/TransWarp/HomePage

AspectC++
- A set of C++ language extensions to facilitate aspect-oriented programming with C/C++. Currently just a research prototype. [Freeware]
- http://www.aspectc.org/