What used to be Project Janus on Solaris® has changed names to BrandZ on OpenSolaris™.
There seems to be some licensing issues using other Enterprise Linux distros with BrandZ. (Not really an issue, you just have to pay for a license.)
CentOS is listed as working with BrandZ and solves this problem (like we solve it for other people all the time). 
Anyone running CentOS in OpenSolaris™ using BrandZ ... let us know about it on our BrandZ forum thread (There are also installation instructions and links to other BrandZ / CentOS articles in the forum thread).
BrandZ will become Solaris Containers for Linux Applications (SCLA) on Solaris®
The CentOS Development Team would like to thank OpenSolaris™ (and Sun Microsystems) for including CentOS as one of the supported OSes in BrandZ and we are currently working with Sun Microsystems to make BrandZ/SCLA with CentOS a success.
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