Open Nettest - Open Nettest is a platform for collecting, processing and visualizing data related QoS and QoE.
Ping Meter Gadget - Customizable, graphical, semi-transparent ping (latency) meter.
Fping (open source) - fping is a program to send ICMP echo probes to network hosts, similar to ping, but much better performing when pinging multiple hosts.
PingDoctor - PingDoctor is software that is considered to be the most powerful and easiest to use network route analyzer.
OpenSpeedTest - Broadband Internet Speed Test Unlocked!
noping - C library for ICMP pings