@ttscoff have you ever thought about making Marked for Linux? I've used a Mac since 1996 and my main computer now has Linux installed for the past week. The only real downside of Linux is the 3rd party software ecosystem that I've become used to on the Mac. Marked is part of that.
@reinier I've never developed for Linux (or Windows), so I wouldn't know where to begin. I wouldn't rule out the possibility of learning, though.