Sun's plan to release Solaris under its CDDL open source license got a boost yesterday with an endorsement by...The SCO Group? (This cute Linux penguin keychain from Promotion Potion doubles as a stress ball.)

"We have seen what Sun plans to do with OpenSolaris and we have no problem with it," is the way eWeek's Steven Vaughan-Nichols quoted SCO's Darl McBride in a conference call yesterday.

The question is, with friends like these, does Sun need enemies?

Sun's CDDL has been controversial among open source purists. The license restricts what you can do with the Sun software. Still, the license has been approved by OSI (meaning it can be called an open source license), and Computer Associates wants to build a template from it that will cover all commercial open source.

Despite continuing setbacks in its legal battle with IBM to establish ownership of Linux, SCO still acts like it's the one and true owner of all Unix, and thus all Linux. Now, it seems Sun has bowed to that contention -- that's how SCO is trying to spin things anyway.

I'm waiting to see what comment Sun COO Jonathan Schwartz makes about this on his blog, if any.

His silence might speak volumes.