In an internal memo to staff, which has apparently been leaked, Oracle says it will no longer support the project apart from releases of package updates under the same licence (the CDDL or Common Development and Distribution Licence) for future releases of Solaris 11 Express.
"All of Oracle's efforts on binary distributions of Solaris technology will be focused on Solaris 11," the memo says.
"We will not release any other binary distributions, such as nightly or bi-weekly builds of Solaris binaries, or an OpenSolaris 2010.05 or later distribution.
"We will determine a simple, cost-effective means of getting enterprise users of prior OpenSolaris binary releases to migrate to S11 Express."
Like many other community projects, OpenSolaris was begun in 2005 as a means to encourage developers outside of Sun to contribute to development.
This method of development has been responsible for the rise of Linux and its numerous distributions - companies like Red Hat and Novell have benefitted enormously from their community distributions, Fedora and OpenSUSE respectively.
Even though Sun was always more than a bit restrictive in its attitude towards OpenSolaris, the project had managed to produce a number of good releases. But it does not generate any income directly - and Oracle's focus appears to be the money-generating parts of what it bought.