As a curious fellow who is interested in system stability, I would like to know Is There A Way to keep open X clients running when the X server dies? Then, upon restart of X, Everything Just Comes Right Back.

I've never seen this done before, but I'm certainly curious to know if it is possible somehow. Perhaps something extra required client-side? (upon disconnect, auto save-state and reconnect?)

I appreciate any information on the matter, thanks.

kde can do this.
beyond just opening the apps though its up to the individual apps to know what they were doing.

the problem is if an application is causing the crash then restarting it ... well causes another crash ad infinitum.

What KDE can do is keep list of What Programs Happen To Be Running, and then just exec everything on that list upon your login.

But! Let's say I have an OPEN UNSAVED DOCUMENT in OpenOffice. X crashes, I lose my work.

I find this very unsatisfactory.

My experience with X crashes so far very often is related to vterminal/X switching, with the Nvidia drivers. Certainly there are bugs in Nvidia's driver, but certainly there's no better alternative. I like to use my hardware in the capacity which I paid for.

Alas, no definitive answer yet. Is it, in fact, the individual client's responsibility to save its state in case of an X crash? Or is there a more clever way?

Use (x)emacs.
(A) It auto-saves; (trivially) you won't lose work.
(B) After you eval gnuserv, you can (in an X session) execute gnuclient to attach to the running emacs, where you'll find all the buffers open and in the state you last touched them. I use this to continue across network glitches, which terminate my ssh session and the X11 forwarding across it. I start the main xemacs process as follows,
The first is sh/bash syntax to unsetenv DISPLAY, so that the xemacs will survive loss of the X server. I run an unmapped xemacs inside screen (also unmapped) to make it immune to hangups.

Well, that's just an individual app, but highly useful to me. A more generic approach might be vncserver, which starts Xvnc. "It is based on a
standard X server, but it has a "virtual" screen rather than a physical
one. X applications display themselves on it as if it were a normal X
display, but they can only be accessed via a VNC viewer".