I just found out that SwiftMQ (a Java messaging router) has gone commercial. They were never open source but the product was free prior to February 2002. From this event I have learned something which I believe is very important: Making something free and making something open source are two TOTALLY different things.
I have decided to never use another free, non-open source product for development or production systems from this point on. If something is free but not open source then I will not even bother installing it. While I don't mind paying for good products, it disturbs me greatly to be screwed when a free product "converts" to a commercial product.