Apple's Monday WWDC keynote included a quick-fire presentation about gaming content on Macs—but the biggie was VR, along with a path for underpowered Mac systems to potentially get up to speed to running it.

Senior Vice President Craig Federighi confirmed that "Valve is bringing SteamVR to Mac." Soon after, Industrial Light and Magic demonstrated the first-ever native HTC Vive demo on a Mac system. An Epic Games staffer dropped TIE Fighters, Imperial Cruisers, and Darth Vader into a Star Wars-themed world, using nothing more than an on-screen GUI controlled with HTC Vive wands.

While newer home Mac systems will come with the kind of horsepower needed to render HTC Vive-ready content at a comfortable 90 frames-per-second refresh (a number that ILM said they had reached with their demo), Federighi also announced a new GPU enclosure for less-powerful Mac systems. It will connect via Thunderbolt 3 and come equipped with an AMD Radeon RX 580 video card. Developers will have first dibs on this enclosure, as it will debut as a "dev kit." No release date or price was confirmed, nor did Apple comment on options for older systems without TB3 support.

SteamVR will be joined on Mac systems by the Unreal and Unity video game engines, which will tie directly into today's newly announced Metal 2 video-processing API. Federighi insisted that Metal 2 offers up to ten times better draw call improvement than the original Metal API and runs "100 times" better than OpenGL.

The combination of HTC Vive headsets and SteamVR branding seems to indicate that Apple is ceding VR hardware development to outside partners, at least for now. It's also another major blow in the battle between HTC Vive and Oculus Rift for leadership in the high-end VR category. Microsoft previously put Oculus Rift in the spotlight before turning its attention to the Microsoft Holographic line of low-priced, third-party VR headsets.

This article has been updated to clarify Thunderbolt 3 details.