Using the xmosaic-0.9 and -0.10 distribution binaries,
I have encountered crashes on a variety of servers:
MIT X11r5 on DEC with DEC xmosaic
MIT X11r4 on Vax with AIX xmosaic
MacX on Mac with Sun xmosaic
But, is beta code, right?
Well, apparently mine is the only bug report on this.
Thus the NCSA folk responded that it was the "fault" of the servers.
So, if you have a server crash, I suggest you email firstname.lastname@example.org,
so the problem's magnitude can be guaged.