- OpenSolaris is an open source version of the Solaris operating system originally developed by Sun Microsystems. It includes code from Solaris and various open source software.
- The OpenSolaris project aims to develop the operating system collaboratively with the community. Sun contributed code under an open source license and future versions of Solaris will be based on OpenSolaris.
- Notable releases include OpenSolaris 2008 which included the GNOME desktop environment and the ZFS snapshotting Time Slider feature, as well as preinstallations on Toshiba laptops in 2008-2009. The Caiman project is developing an updated installation experience.