Getting Started with OpenSolaris
OpenSolaris(.com) was the official distribution of the OpenSolaris(.org) project, released by Sun Microsystems. It was originally released on the 5th of May 2008, although the OpenSolaris project and codebase dates back to 2005. The final stable release was on the 1st of June 2009 (named 2009.06), with the final preview build being snv_134b, released on the 12th of November 2010, before the distribution was cancelled by Oracle (who has bought Sun Microsystems). This also brought an end to the OpenSolaris project as a whole, as the codebase was no longer updated by Oracle themselves. The project survives however, in the form of OpenIndiana, and illumos.
What is OpenSolaris
Firstly, it's important to establish that OpenSolaris is in no way a Linux distribution. It is instead (mostly) based on Solaris 10, which is in turn based on System V Unix. However, it does contain a decent amount of open-source software, such as the GNU Utilities, and GNOME, and therefore the workflow can be similar. It is important to note that while OpenSolaris is based on Solaris 10, it is not directly, instead being based on a community supported open-source codebase also called OpenSolaris. Before 2008, Sun did not have their own distribution of this, instead there were other community distributions such as BeleniX, MilaX and NexentaOS. It was available for both Intel x86, and Sun's own SPARC architectures.
A brief history
In 2005, Sun began an initiative to open-source parts of their Solaris OS, starting initially with their "DTrace" technology, over the course of the year, the source code to Solaris 10 (99% of it anyways), including 1670 patents, were released under the CDDL (based on the Mozilla Public License).[1] This was in an effort to establish an open-source community around the operating system, and allowed contributions to the codebase. Naturally, Sun retained the Solaris trademark. Everything was located at OpenSolaris.org.
In 2007, the founder of Debian was hired[2], to form a new project called "Project Indiana", this was an effort by Sun to create an official distribution, that included both GNOME and GNU utilities. The result of this was the OpenSolaris distribution, released in 2008, available at OpenSolaris.com, and designed as an entry point into the community.