I have a fresh OpenSuse 13.1 installation with all updates installed.
ruby 2.0.0p247 (2013-06-27) [x86_64-linux]
sudo gem install sass
sudo gem install compass
It looks like openSUSE patches rubygems to keep multiple ruby versions installed, so it appends version number to files in bin/.
I've tried install sass package on my Linux x86_64 system and it produced
sass, scss and sass-convert executables without extension.
I'd also warn to install gems this way, directly into filesystem. I'd recommend not avoiding package management and install through properly built packages. At openSUSE's wiki there is paragraph about how to package Ruby gems into rpms .