I just found out today that main development by the original authors of HTMLArea has been discontinued. See the bottom of the Dynarch project page for some more details, reproduced here:

Update, March 8 2005. Some time ago, InteractiveTools expressed the will to take over the project. We provided some fixes that we made and were not in the CVS version and a RC2 was released at htmlarea.com; however, soon thereafter InteractiveTools announced the project closed and forums discontinued. Bang!

Our position on this is that the editor will keep going; we are actually making quite some progress in its development, but only in house at this time. We are still planning to release version 3.0, quite possible under a different name (so it might actually be a 1.0) but still free, at least for the core editor--some plugins might be released under a commercial license. We can't provide explicit deadlines, so please bear with us.

I also checked the licensing, and it is in fact the case that HTMLArea is not GPL -- it is a modified BSD license. As we discussed at DrupalCon, I believe this is an issue for having that code here on Drupal.org. All code, including contrib, needs to be under the GPL.

Finally, I wanted to make a general call for all people interested in development of WYSIWYG editing for Drupal to respond here. I believe we can now focus our efforts on the FCKEditor codebase (ideally with a different module name -- like richtexteditor.module or something).