I can't find aMSN in the Scientific Linux 6 repositories.. How can I install it?
Well if there's no packaged binary for your distro you can try building the package from source. Get the gzipped tarball and extract it somewhere you do your build-related stuff, and follow the standard procedure:
Here you make sure to read all important files, such as
I just googled for "amsn el6 rpm" and got tons of hits. So you can download an already built rpm and install it.
el6 is short for RedHat Enterprise Linux 6 - which is the "orignal" OS for the binary compatible clones (CentOS 6, Scientific Linux 6).