A few years ago (ok a LOT) I had written a VERY simple network monitoring system for work. It primarily gathers syslog events, and does a basic TCP connect to check on machine state. This uses MSDE as it's engine for events.
A Windows multithreaded application written in C#.Net designed to provide automated discovery and processing of various forms of source data. Each feed can be processed according to a basic syntax. All input parameters are defined by XML.
FulbotPHP is a simple IRC bot totaly written in PHP via socket functions. FulbotPHP can handle most of the basic IRC commands, but not any automatic features like floodprotection YET!.
Visual Network Manager (VNM) software manages your critical network assets across your entire infrastructure, integrating disparate data from multiple vendors, protocols, and legacy systems into a single web portal.