Solution 1:

There may not be much hope with Join.me of a good cross-platform presentation solution.

For over a year Linux support has been the second-most-popular request on the official join.me Ideas Forum and there are over 1800 votes for the idea:

  • Make a version compatible with Linux/Ubuntu 12.04 – join.me forum and faq.

But join.me does not seem to even be willing to comment on the thread.

Alternatives

But there are many alternatives. According to comments there, WebEx, Mikogo and Yuuguu support presenting from Linux, and others mentioned are Tightvnc, BigBlueButton and TeamViewer.

Update: And of course now add to the list: Jitsi Meet, Zoom, Hangouts Meet, Skype, and many others which use standardized web technologies and are highly cross-platform.