GEOS is a C++ port of the Java Topology Suite.
It is used by several fossg products including postgis and geo-django.
See GEOS on this page for some good instructions: http://geodjango.org/docs/install.html]
installation
$ wget http://download.osgeo.org/geos/geos-3.1.0.tar.bz2 $ tar xjf geos-3.1.0.tar.bz2 $ cd geos-3.1.0 $ ./configure $ make $ su $ make install $ exit
Read this if you have issues.