Game distribution service Steam is beginning to expand its horizons this September, beginning with the sale of non-gaming software.
Starting September 5th, you'll be able to purchase an array of software from Steam that aren't just games. While no programs were announced, they will include both "creativity and productivity" applications and benefit from Steam much in the same way games do. They'll have easy, automated installation, automatic updating, and your data can be stored in the Steam Cloud.
This won't be the first instance of non-gaming software on Steam. A film, Indie Game: The Movie, was sold on Steam exclusively, marking the first film sold via Steam. Later, Valve launched their filmmaking and animation program Source Filmmaker, which lets users create film and animation inside Valve's Source engine.
Source