In an important expansion to its in-house gaming efforts for years, Valve has announced today that Steam users can now transfer games from their PC game libraries to devices outside the home. [1
The only requirements for today's "early beta" version, according to the announcement, are that "your computer has a good upload speed and your Steam Link device has a good network connection". These are imprecise terms, of course, but Steam's in-house streaming has shown in the past a good ability to scale visual quality up and down based on network conditions.
Valve's announcement comes a few days before Google announces its game and hardware streaming service at next week's Game Developers Conference. But that service will probably mirror other subscription services like GeForce Now or PlayStation Now, which send a selection of games running on powerful centralized servers. Steam Link Anywhere is more like Nvidia's GameStream service, which essentially allows your home game system to serve as a streaming game server you already own.
Just last week, Sony released the new PS4 firmware that allows users to broadcast PS4 games to their iOS devices, expanding a capacity that was already available on Android and PlayStation Vita.