The problem with iXAFS is that it is attempting to run a 32 bit version of perl contained within the application in a 64 bit process. The new version of perl that ships with Snow Leopard is 5.10.0. I pasted the error message from the ixafs shell below. The solution would seem to be to repackage the perl libraries in 5.10.0 and use 64 bit binaries for the Intel compiler. I have the Intel compiler as well so if you need help, please drop me a line. Note Perl 5.8 is included with Snow Leopard as well and can be invoked by changing the defaults of the system, but this is probably a bad thing to do as it will change the perl application for all programs and will undoubtably cause more problems in the long run than it will solve. Cheers, Paul p.s. lines below are from perl and iXAFS under Snow Leopard (10.6.1) $perl --version This is perl, v5.10.0 built for darwin-thread-multi-2level (with 2 registered patches, see perl -V for more detail) Copyright 1987-2007, Larry Wall athena Can't load '/Applications/iXAFS.app/Contents/Resources/Horae/lib/perl5/ site_perl/5.8.6/darwin-thread-multi-2level/auto/Tk/Event/Event.bundle' for module Tk::Event: /Applications/iXAFS.app/Contents/Resources/Horae/ lib/perl5/site_perl/5.8.6/darwin-thread-multi-2level/auto/Tk/Event/ Event.bundle: no appropriate 64-bit architecture (see "man perl" for running in 32-bit mode) at /System/Library/Perl/5.10.0/darwin-thread- multi-2level/XSLoader.pm line 67. at /Applications/iXAFS.app/Contents/Resources/Horae/lib/perl5/ site_perl/5.8.6/darwin-thread-multi-2level/Tk/Event.pm line 10 Compilation failed in require at /Applications/iXAFS.app/Contents/ Resources/Horae/lib/perl5/site_perl/5.8.6/darwin-thread-multi-2level/ Tk.pm line 13. BEGIN failed--compilation aborted at /Applications/iXAFS.app/Contents/ Resources/Horae/lib/perl5/site_perl/5.8.6/darwin-thread-multi-2level/ Tk.pm line 13. Compilation failed in require at /Applications/iXAFS.app/Contents/ Resources/Horae/bin/athena line 64. BEGIN failed--compilation aborted at /Applications/iXAFS.app/Contents/ Resources/Horae/bin/athena line 64. Undefined subroutine &Tk::Event::CleanupGlue called at /Applications/ iXAFS.app/Contents/Resources/Horae/lib/perl5/site_perl/5.8.6/darwin- thread-multi-2level/Tk/Event.pm line 3. END failed--call queue aborted at /Applications/iXAFS.app/Contents/ Resources/Horae/bin/athena line 64.