http://geniisoft.com/showcase.nsf/WebEditors - chart comparing many editors. The only three I saw that are widely compatible and not proprietary are Cross-Browser RTE (Creative Commons attribution license), Ekit (Java, and the demo gave me a popup requesting access :-P), and Xinha (no development since June last year, seems sporadic but they've had other long breaks).

Here's a 2009 chart comparing a few editors that Drupal can use: http://drupal.org/node/208456

As for activity, that first chart has TinyME as "abandoned", but their github page looks reasonably active https://github.com/tinymce/tinymce I suppose it would still be a good idea for someone to hang out in their developer forum a bit and see if the new team has their heads on right, but frankly I'm not seeing any viable alternatives. A quick search for a Ruby-coded HTML editor turned up nothing. --John Abbe

I'm on this, John. I wanna make a shiny new editor comparison chart or find one. I did find wikimatrix.org and I'm wondering if wagn could somehow get into that arena.

  --cquin.....2013-03-02 03:31:54 +0000

We're already there.

  --John Abbe.....2013-03-22 09:05:26 +0000

Tagged Wagn 1.11 in preparation for build link and inclusion editors --John

not related. this is about moving away from tinymce.

  --Ethan McCutchen.....2013-03-22 20:37:22 +0000

Which we still want to do, but it's no longer something we foresee happening in the near-term. It's not that we want a better text editor, but that we want something more akin to a page layout tool.

  --John Abbe.....2013-03-22 22:55:30 +0000