Sun Microsystems is expected to release Solaris as open-source software Tuesday; the move is a centerpiece of the company’s plan to regain lost relevance and fend off rivals Red Hat, IBM and Microsoft.

The company plans to post more than 5 million lines of source code for the heart of the operating system–its kernel and networking code–at the OpenSolaris Web site, said Tom Goguen, Solaris’ marketing chief. However, some source code components, such as installation and some administration tools, will arrive later.

Source: News.com