[I think my messages are getting out now.] Jan Vroonhof <vroonhof(a)math.ethz.ch&gt; writes in xemacs-beta(a)xemacs.org: What is different from FSF Emacs is that XEmacs allows usage of mmap for allocation *after* dump. I checked the FSF Emacs source very carefully and the version I looked at had it always disabled, by apparent accident. When mmap is used for allocation with the Doug Lea malloc, the addresses returned can conflict with Emacs tag bits in the high-bits range of the address, hence ... Because the tag bits stomp on part of the return address pointer *when mmap for allocation is enabled*. FSF Emacs has to turn mmap off because they don't have the option of minimal tag bits. It was not luck, except the fortunate circumstance that Kyle implemented it around the time I ready was to use it. Is that a problem? We don't free *anything* starting just before exit(3) is called (the voodoo_free_hook hack). This is due to the way egcs/gcc-2.9 has unconditional support for constructors & destructors. Bypassing free(3) at exit(3) time unconditionally also bypasses all destructor calls. I made a test on Demeter last night before she died, and I could not reproduce the exit(3) crash described above, but that may be due to differences between glibc-2.1 and glibc-2.0.7preX, or something else. I have upgraded practically everything between March of 1998 and now. -- I protest the NATO war in Yugoslavia.