INSTALLATION INSTRUCTIONS:
----------------------------------

The file sage-x.y.z-i686-Linux.tgz, which you download here,
contains a pre-built version of SAGE that can be decompressed
into a directory and run from there.  Just type

   tar zxvf sage-x.y.z-i686-Linux.tgz

then change into the resulting directory and type "./sage" to 
run SAGE.  You can move the directory wherever you want afterwards too.

NOTE: SAGE is also fairly easy to build from source on Linux. 

64-bit: 
You can use this on both 32-bit and 64-bit Linux computers.  On an
opteron 64-bit machine, you'll get better performance (and use of more
than 2GB RAM) by using the binary that is built specially for that
machine instead (which is in another directory).  Look in the linux_64bit
directory.