I'm looking for an actively-developed C# framework for Aspect-Oriented Programming. It seems like there are lots of choices for Java, but I've been struggling to find a good, free choice for C#.
PostSharp seems like a reasonable choice, but it costs $400, which is a lot given that this is still just a demo.
The closest I've been able to find for an answer so far is this list, but it's about 4 years old at this point and seems quite out-of-date; for example, it lists Spring.NET as being under active development, even though the last announcement I see on the framework's web site is from December 2012, so I'm assuming that it's no longer under active development (correct me if I'm wrong).
Does anyone have any recommendations?