OpenIndiana is a free and open-source Unix operating system derived from OpenSolaris and based on illumos. Forked from OpenSolaris after OpenSolaris was discontinued by Oracle Corporation, OpenIndiana takes its name from Project Indiana, the internal codename for OpenSolaris at Sun Microsystems before Oracle’s acquisition of Sun in 2010. Created by a development team led by Alasdair Lumsden, the OpenIndiana project is now stewarded by the illumos Foundation, which develops and maintains the illumos operating system. The project aims to make OpenIndiana “the de facto OpenSolaris distribution installed on production servers where security and bug fixes are provided free of charge.

Origins
Project Indiana was originally conceived by Sun Microsystems, to construct a binary distribution around the OpenSolaris source code base. Project Indiana was led by Ian Murdock, founder of the Debian Linux distribution. OpenIndiana was conceived after negotiations of a takeover of Sun Microsystems by Oracle were proceeding, in order to ensure continued availability and further development of an OpenSolaris-based OS, as it is widely used. Uncertainty among the OpenSolaris development community led some developers to form tentative plans for a fork of the existing codebase. These plans came to fruition following the announcement of discontinuation of support for the OpenSolaris project by Oracle.
Initial reaction

OpenIndiana operating in console mode.
The formal announcement of the OpenIndiana project was made on September 14, 2010, at the JISC Centre in London. The first release of the operating system was made available publicly at the same time, despite being untested. The reason for the untested release was that the OpenIndiana team set a launch date ahead of Oracle OpenWorld in order to beat the release of Solaris 11 Express.