http://blogs.msdn.com/jmstall/archive/2006/08/30/exitprocess-versioning.aspxHere's an example of an API versioning problem. In general: Anytime you take two separate concepts and tie them together based off some current implementation assumption, you're going to get trouble when that assumption is broken. The specific exampleen-USCommunityServer 2.1 SP1 (Build: 61025.2)http://blogs.msdn.com/jmstall/archive/2006/08/30/exitprocess-versioning.aspx#734589Fri, 01 Sep 2006 05:42:33 GMT91d46819-8472-40ad-a661-2c78acb4018c:734589Jason Haleyhttp://blogs.msdn.com/jmstall/archive/2006/08/30/exitprocess-versioning.aspx#734590Fri, 01 Sep 2006 05:43:26 GMT91d46819-8472-40ad-a661-2c78acb4018c:734590Jason Haleyhttp://blogs.msdn.com/jmstall/archive/2006/08/30/exitprocess-versioning.aspx#735441Fri, 01 Sep 2006 18:44:57 GMT91d46819-8472-40ad-a661-2c78acb4018c:735441Brian TylerHmmm, I've not used the .NET 2.0 hosting APIs yet, but I hadn't realized that it didn't allow you to recycle the CLR you're hosting...do you know if that's a planned feature for the future? I know that it would be very handy for harnesses - such as a test harness - to run through code in different versions of the CLR. <br> <br>Regardless, I'll throw in my vote - keep the correct semantics based on what you named it. It'll cause short-term pain for redesigns, but that is nothing to the entropy increase by having nonsensical behavior to future programmers. Entropy is unavoidable, but that doesn't mean you have to take it out to dinner :)http://blogs.msdn.com/jmstall/archive/2006/08/30/exitprocess-versioning.aspx#735804Fri, 01 Sep 2006 23:32:50 GMT91d46819-8472-40ad-a661-2c78acb4018c:735804Mike Stall's .NET Debugging BlogIt's tough to make a client use your API correctly. It's especially tough to get clients to not do things...