I mean if it's built in the browser it's likely using WebRTC under the hood. Might not be the same techniques they described in their article but all the negotiation and transport is built on open source then. Likely also using MS Desktop Duplication API and Media Foundation.
Not sure why the time you started building it matters but hasn't moonlight-chrome been around for even longer? https://github.com/moonlight-stream/moonlight-chrome