To get VisualOberon working you have to install a number of software packages. While the first one is definitaly needed, the second one is optional, but I would highly urge you to install it.
Installation is simple.
After having the compiler running, you have to install another OS-dependend library for the compiler. Installtion of that module sis rather simple, too. It all comes down to run configure and make install with root rights. After that you can finaly install VisualOberon itself. Installation is similar to the installation of oo2c.