Hi Shashi
To be realistic, a first version for Mac OS X won't be released before 2008. We are currently overwhelmed with the amount of work that we have now (finishing a first commercial release, writing documentation, tutorials, ...) so we simply cannot afford porting PixInsight to other platform now.
PixInsight for Linux is being developed mainly on Fedora Core 6, so no surprise if it runs without flaws on your FC6 for x86_64
A first version for x86_64 should be ready soon. The only thing that is stopping us now is that we are having some troubles to compile a few support libraries with 64-bit GCC. The rest of the platform compiles without problems as native 64-bit code. This should be fixed really soon.
Regarding your Mandriva 2006, the problem is quite probably that certain system libraries are not up-to-date. If you want to make an experiment, you can download this file:
http://pleiades-astrophoto.com/export/PI32-linux-oslibs-20070609.tar.bz2and unpack it on the same bin directory where you have PixInsight32.sh (install the new build 293 first). If you are running a SELinux-enabled system, don't forget:
chcon -t texrel_shlib_t *.so*
on the same directory, in order to allow execution of the new shared objects.
With these new files, hopefully the PixInsight application will load all necessary shared libraries from the bin directory, and hence there will be no conflicts and it will run without problems. This is experimental, however. If you try it, I'll be very interested in knowing how it goes.
Thank you.
Juan