A Clarification Regarding Java

In a previous post I wrote about how RMS’s essay on writing free software for Java struck a chord with me. In summary, RMS states that writing free software in Java that uses JRE features not available in free software Java implementations (such as the GNU Classpath ) reduces the actual freedom of that software. I drew a parallel between non-free JRE features and Mac OS X-specific free software. It seems to me that free software, written to target Mac OS X only, is not really free. I consider myself a pragmatist about many things, and I think this view fits: I use both Linux and Mac OS X and it’s frustrating when I can’t use the same software in both places.

OK, on to the point: I was thinking about this again in the shower this morning (I’m not really sure why), and I realized there is a pragmatic difference I failed to mention previously. I don’t code in Java regularly, mostly because I just have never had a compelling need. However, it does seem to me that there is a pragmatic difference between free software “constrained” by non-Free, zero cost software and that constrained by non-Free, costly software. That is, does that fact that Sun and IBM give away their respective JREs make the constraint more palatable than the constraint of Mac OS X, which as we all know costs money? Does, or should, the question of monetary cost enter into the equation of how Free software is?