There are a lot of great bandwidth testers out there (DSLReports, Speakeasy, etc.) but no free/open source solutions I could find. The problem with a hosted bandwidth tester is that your results are subject to their bandwidth. By having one of my own I can drop it on any computer and test the connectivity between them. This project is no longer under development, but I was looking to build more functionality into it, including traceroute utilities and other monitoring/troubleshooting tools… VoIP, QoS, etc. This utility is implemented using a Java Applet with a Swing UI, and it tests uploads by making calls back to a Servlet. It can therefore be conveniently packaged up in a WAR file and dropped into Tomcat as a webapp.