I tried manually installing (dpkg -i) the latest version in Gutsy, but it had too many dependencies. So I decided to try and backport it, and it worked!
I haven’t set up any repository, so just download the below two .deb files and install them with sudo dpkg -i *.deb in a terminal window:
The md5sums for these files are:
3f0a962ffdd2974663f2f425eed5f541   libslab0_0.9.8.svn.20070430-1ubuntu1_i386.deb