Cross platform support will absolutely be a priority when Replay is on the official roadmap.
Thanks for the feedback, firefox-replay.com is also a work in progress. We did not plan an official release today.
We'll be sure to make the Mac OS limitation more clear.
Here is some more context on the mac specific functionality (https://searchfox.org/mozilla-central/source/toolkit/recordr...).
A question about how you develop / roll this out. Do you keep the code private, or do you commit it to the open source repo as you're working with a small amount high touch users?
I guess the question is do you want a full working product when you open source it? Do you tie your PR / forum posts with publicly shipping the source code? Or is all development out in the open?
Everything is in firefox and open source
Here are the bugs: https://bugzilla.mozilla.org/buglist.cgi?cmdtype=runnamed&na...
Here's the primary directory: https://searchfox.org/mozilla-central/source/toolkit/recordr...
The debugger API is implemented in JS here https://searchfox.org/mozilla-central/source/devtools/server...