What began with a limited Beta that saw over 60,000 people originally sign up for testing, Valve quickly expanded to a fully public release in December of 2012 and then onto a proper release in February 2013. During that time we've seen many ideas rise and fall, including Steam Machines and SteamOS but Valve continues onwards with Linux anyway. They continue working with various companies and individual contractors on various projects. Here's just a small slice of what they've been doing
Steam has now been available on Linux, at least in Beta, for eight years now and it's come a long way.