The server is designed with a "plug-in" module system. Any feature that is not needed can be removed from the configuration. Once it is removed from the configuration, it does not affect server performance, memory use, security, etc. This flexibility enables the server to run on platforms ranging from embedded systems (e.g. LinkSys WRT54G) to multi-core machines with gigabytes of RAM.

The module system permits simple integration of new features, as the modules ave complete control over the processing of a packet. For example, the python module adds support for the Python language in less than 500 lines of C. The eap2 module adds support for more EAP types, in just over 500 lines of C.

On-line versions of the man pages exist for most modules.