Oxygen 9.0 Is Out
And now, it looks like I can finally re-evaluate my XML editor needs, too. So far, I've run XMetaL in wine, which kind of works except that right-clicking the workspace still crashes the program (but that's fairly OK since I seldom need to right-click anything while writing). As most things in wine, it's beta quality, no more.
Now, however, Oxygen 9.0 comes with a semi-WYSIWYG view, with CSS formatting and start- and end tag symbols, making it the first real alternative to running Windows software in wine. It is reasonably fast, too, from what I've seen so far, and certainly more stable than anything run in wine. You do need an official Sun Java JRE, though; it will complain if you use some of the Java replacements available for Linux, and it doesn't work with the GNU libgcj Java Virtual Machine.
I'll give it a more thorough test run within the next week or so, but I'm hoping that it can deliver what it promises.