OpenSolaris

OpenSolaris is an open-source Unix operating system based on Solaris, released by Sun Microsystems in 2005 to invite public participation in Solaris development. It provided a freely available reference implementation of Solaris technologies and served as a platform for collaboration between Sun engineers and the broader community.

OpenSolaris highlighted several notable technologies, including the ZFS file system, the DTrace dynamic tracing framework, and Solaris Containers (zones) for lightweight virtualization. It also offered advanced system administration tools, networking capabilities, and a development environment designed to encourage community contributions. The project was released under the Common Development and Distribution License (CDDL), with public access to source code and build infrastructure.

In addition to core technologies, OpenSolaris introduced a modern packaging and development workflow aimed at enabling experimentation and rapid iteration. The project fostered an open development model, allowing users to track progress, contribute code, and test new features before they were incorporated into Solaris or downstream distributions.

After Oracle Corporation acquired Sun Microsystems in 2010, Oracle discontinued OpenSolaris as an official project. The open-source codebase and community activity shifted to the Illumos foundation, which led to derivatives such as OpenIndiana and other Illumos-based distributions. Oracle Solaris continued as Oracle’s commercial Unix offering.

OpenSolaris is remembered for making Solaris technologies accessible to a broader audience and for demonstrating how an open-source model could support innovation in a proprietary Unix lineage. Its influence persists in subsequent Solaris developments and in open-source Unix ecosystems that followed.