On Feb. 4, the Symbian Foundation will release the first completely open-sourced version of its mobile phone operating system, a move it hopes will make it easier for developers to improve the software and create applications for use on Symbian-based phones. Starting tomorrow, programmers will be able to download, modify and use the software at no charge. The organization made pieces of its code available earlier.

The release marks the conclusion of the huge effort to turn Symbian, the most commonly used smartphone software, from a proprietary operating system only available to developers at companies like Nokia into an open-sourced one, accessible to programmers around the world. Symbian engineered the move as rival Google made a splash with Android, a rival open-source mobile operating system that’s gaining steam. By 2012, Android will surpass Windows Phone and the iPhone to become the world’s No. 2 most popular mobile operating system behind Symbian, according to Gartner. As rival software gained market share, support for Symbian began to flag. Symbian hopes the new, open-sourced software will help reverse the slide. “We’ll see proliferation of converged devices based on Symbian happen this year,” says Larry Berkin, general manager for Symbian in the U.S.