iperf - A TCP, UDP, and SCTP network bandwidth measurement tool
Visualping - Visualping is the easiest to use website checker, webpage change monitoring, website change detector and website change alert software of the web. Read more about Visualping.
JPerf - This project gives a better UI and new functionalities to the initial JPerf 1.
Distill Web Monitor - Distill is a web monitoring tool. It can monitor RSS feeds, a webpage or a part of webpage. Alerts in the form of pop-up, audio or emails can be received.
netperf - Netperf is a benchmark that can be used to measure the performance of many different types of networking. It provides tests for both unidirectional throughput, and end-to-end latency. - HewlettPack...
Update Scanner - Update Scanner is a Firefox extension to monitor web pages for updates.