Netdisco is written in Perl and self-contained apart from the PostgreSQL database, so is very easy to install and runs well on any linux or unix system.
It includes a lightweight web server for the interface, a backend daemon to gather data from your network, and a command line interface for troubleshooting. There is a simple configuration file in YAML format.
Please check out the installation instructions on CPAN.
Some of the things you can do with Netdisco: