I muttered about Sun using the GPL for their OSS efforts a while ago, and there has been very little information about it in public, until now, and the whole industry is buzzing.
Jonathan Schwartz mentioned CDDL at the end of October, but that's been the only thing out there, and that was clearly an unscripted moment.
CRN posted this piece on Sun using the GPL, and - well - this supports what has been my bet for some time now.
Why? Because I think I understand now what Sun wants to achieve - basically, a 'walled garden' for its customers and partners, where they can create a stronger relationship, a participatory relationship, with those that still wish to be dependent on Sun for things like tested binaries, and such.
In retrospect, it's an easy conclusion to come to. Safe money bets that Sun will retain the same IP model they use for Glassfish and OpenSolaris, namely require that Sun is granted joint copyright ownership of any contribution, with the result that Sun will have a complete copyright and thus will be able to relicense to others under commercial terms. This creates a tilted "playing field" in Sun's favor, which I think is a mistake. It will discourage collaboration by Sun's licensee-competitors, which is a wonderful use for open source. There are countless examples of it, such as linux, httpd, tomcat, etc - but it relies on an equality in the ecosystem that Sun's model doesn't support. The GPL is the only logical license that supports this level of control. Other licenses, such as the BSD, MIT, CDDL, Mozilla, etc allow a recipient to freely augment or replace pieces and license those changes under their own license. That removes the control point that GPL gives Sun.
Sun's business model these days is 'open access and trial, come back for support and service'. So they will make things accessible for people to read, review, run, inspect, etc. The GPL is a great vehicle for this - it lets them retain control over who can make a proprietary derivative work, yet allow people to read and inspect it under a license that is "blessed" by the OSI.
So, it's a logical move in support of the "walled garden", one that fits what Sun appears to be doing as their global business model. It's a proven model, as demonstrated by MySQL, so it will probably work out for them. It does raise some interesting questions though, but that's for another blog....