I made a Multirom image for Firefox OS. I have the Lollipop kernel on my phone and it works pretty decently. The biggest problem for me is that it won’t connect to Sprint’s network, but it might work with GSM - not sure yet. It’s built pulled straight from git, so it’s bleeding edge, and probably buggy. If there’s interest, I can try to build 2.0 rather than Nightly.
Download: (snip, domain expired and build was super old. will update soon(ish?))
It turns out I built this wrong! It works, but there are no apps installed. I'm going to rebuild it later - @yousef and I are working on a build server on DigitalOcean, rather than building locally and uploading (very) slowly.