Ubuntu 10.04 LTS and ifort 11 (x86_64)

Basically you need libstdc++.so.5, thus you can follow the steps in http://www.hackourlives.com/ubuntu-10-04-lucid-lynx-libstdc-so-5/ . My experience on this for my x86_64 virtualbox was that you might not need the 32bit library at all, if you don't have /usr/lib32 .

$ wget http://mirrors.kernel.org/ubuntu/pool/universe/g/gcc-3.3/libstdc++5_3.3.6-17ubuntu1_amd64.deb
$ sudo dpkg --install libstdc++5_3.3.6-17ubuntu1_amd64.deb