[pyrotechnick]

Correct. http://www.infoq.com/articles/java-dotnet-patents

But what isn't? Plenty of Rails is sitting atop JRuby and friends. Nothing is immune.

Don't get me wrong. I'm not a massive supporter of .NET (outside of XNA) by any means. My point is if legal issues are what you're looking for; you'll find them; everywhere. It's just all so ubiquitous it's simply not cause for concern.

Anything can be made to be seen as illegal from a certain perspective. Everyone is suing everyone else. Does that mean we all pack it up and go home?

[knowtheory]

This is by and large a red-herring.

Unless your Ruby app is leveraging JRuby's integration with Java... you can just take your Ruby app, fire it up on Rubinius or MRI, and you're no worse for wear.