cmake at least version 2.4.3. For
many popular distributions cmake is incorporated by default or
at least apt-get (or whatever your distro package installer
might be) is cmake aware. Still, in case you need to install
an up-to-date version cmake's official site distributes many
binary versions (alas packaged as tarballs) which are made available
at http://www.cmake.org/HTML/Download.html. Optionally, you
can download the sources and recompile them: this simple process
(./bootstrap; make; make install) is described at
http://www.cmake.org/HTML/Install.html.