[QUOTE=Unregistered;169512]Downloaded the mprime259.tar.gz from the mersenne.org site and unzipped it. Tried executing mprime but it returns an error saying 'error while loading shared libraries: libcurl.so.3: no such file or directory' . What do I do now??[/QUOTE]

If you are on a Mac - as the thread title would suggest - why not get the mprime version built for Mac OS X?