Valve officially announces the Source Engine 2, saying they will make this available free to content developers. Word is they plan on fully supporting Vulkan, the API formerly known as Next Generation OpenGL. Here's the deal:

Valve announced the Source 2 engine, the successor to the Source engine used in Valve's games since the launch of Counter-Strike: Source and Half-Life 2. "The value of a platform like the PC is how much it increases the productivity of those who use the platform. With Source 2, our focus is increasing creator productivity. Given how important user generated content is becoming, Source 2 is designed not for just the professional developer, but enabling gamers themselves to participate in the creation and development of their favorite games," said Valve's Jay Stelly. "We will be making Source 2 available for free to content developers. This combined with recent announcements by Epic and Unity will help continue the PCs dominance as the premiere content authoring platform."

Also as part of supporting PC gaming, Valve announced that it will be releasing a Vulkan-compatible version of the Source 2 engine. Vulkan is a cross-platform, cross-vendor 3D graphics API that allows game developers to get the most out of the latest graphics hardware, and ensures hardware developers that there is a consistent, low overhead method of taking advantage of products. Vulkan, previously called Next Generation OpenGL, is administered by the Khronos Group, along with other standards such as OpenCL, OpenGL, and WebGL.