To clear up
1. Solaris GA releases ( Solaris 10 u1 - uX ) were never open sourced.
2. Solaris code base was open sourced under the CDDL. The Solaris Express and OpenSolaris distros came out of this
3. Belenix ( http://belenix.org/ ) is a distro created by Moinak Ghosh and Sriram Ram Naraynan ( who is from ThoughtWorks ). It is built on the OpenSolaris code base
4. The word "OpenSolaris" itself means three things a. The distro b. The code base c. the community
5. Most of the OpenSolaris code base is available at http://src.opensolaris.org/source/
6. Thanks to the CDDL, Belenix development can go on.
For any further questions, post to the Bangalore OpenSolaris User Group at mailto:ug-bosug@opensolaris.org