I strongly disagree with what Mark Stone wrote about the unimportance of the right to freely modify Perl.
in reply to Perl and open source
First of all while very few people use the right to freely modify software, that does not mean that it has small value. It has tremendous value. First of all you know that you will benefit from improvements from other motivated people. Secondly you don't have to worry that the project will be abandoned with a sizeable user base left hanging (as often happens with proprietary software when companies die). Thirdly, even if you don't use the option, knowing that you have the option is valuable.
Also I don't know what orifice he pulled his comment about the core Perl development team out of. Certainly his comment does not match my experience. Of course any contribution will have to address concerns about the quality of Perl as a software project (backwards compatibility, how well changes integrate with the philosophy of the language, etc). However I haven't seen that people who have the time and energy to make quality contributions are likely to get rejected out of hand.
Of course he's writing from the perspective of someone who is fond of Java. So he's going to interpret the open source movement from a point of view that minimizes the difference between Sun's almost open source strategy and an actual open source strategy...