Hi, I have a bunch of olded computer that I want to install Linux. They have CPU speed 133 MHz, Ram : 32 MB ... Do you know which Linux (and which version) is the best suit for those ?

distrowatch.com for everything. linux.org for finding some very small distributions. Do not expect to have fun in Gnome or KDE (your RAM and clock speed will keep you fine in the shell though). There are minimalist window managers, such as ratpoison. Perhaps you should try this distro: http://www.distrowatch.com/table.php?distribution=damnsmall

Take 32 Meg of RAM from half the PCs, put them in the others to make a total of 64 Meg of RAM (if possible). Then you'll be able to use a modern distribution with these 133 Mhz machines. Then, you can install a decent distribution such as Redhat 6.1, maybe even 7. You could even still run X-Windows (KDE and/or Gnome), slowly, but surely. You could even run Redhat 9, but probably no X-Windows, then. I use Mandrake 6.1 (basically Redhat at that time) on a 64 Meg Pentium 166 system and it's quite usable even running the newest Mozilla. Otherwise, follow anonproxy's advice and find a niche solution that fits these limited PCs. Good luck and have fun.

< SNIP > I have a bunch of.... < /SNIP > How many exactly? Maybe you want to look at clustering....check out http://www.beowulf.org and http://lcic.org/

If you are thinking about clustering, you might want to look at openMosix, which doesn't require (theoretically) applications that are specifically coded for parallel processing: "There is no need to program applications specifically for openMosix. Since all openMosix extensions are inside the kernel, every Linux application automatically and transparently benefits from the distributed computing concept of openMosix. The cluster behaves much as does a Symmetric Multi-Processor, but this solution scales to well over a thousand nodes which can themselves be SMPs."