Hi Bruce, Hmm, I had a slightly easier experience getting ifeffit running on a "64bit linux machine" (this is a dual Xeon 64EM and Fedora Core 3 for x86-64). I did have to change the PGPLOT makefile from /usr/X11R6/lib to /usr/X11R6/lib64, but I thought this was 1 line. And once PGPLOT installed, the simplest rendition of './configure ; make install' did work to build Ifeffit. I did find a bug in the command-line shell that mangled characters. That fix will be included in Ifeffit 1.2.8 (due very soon, and also fixing the termcap problem, I think). I did not try to get horae to work -- perl/Tk is not installed on this machine so horae wouldn't install anyway. I recall the python build *did* fail with warnings about -fPIC, but I interpreted that to mean that the python setup was somehow mixed 32/64, and I haven't pursued this further. To be honest, I don't know where the best place to check for '64-bit' would be. --Matt