iperf - A TCP, UDP, and SCTP network bandwidth measurement tool
SmokePing - Smokeping is a tool for measuring latency.
JPerf - This project gives a better UI and new functionalities to the initial JPerf 1.
Pingnoo - Pingnoo is an open-source Windows, macOS and Linux visual trace route analyser.
TamoSoft Throughput Test - TamoSoft Throughput Test is a utility for testing the performance of a wireless or wired network.
PingPlotter - PingPlotter is a troubleshooting tool that helps IT professionals and neophytes identify, diagnose, and resolve network issues.