Gatling
Solid, polished load testing tool that outputs beautiful reports with Scala scripting
Open Source and Enterprise support levels for the product
JMeter
Robust API (through GUI) for test script development with no coding required
Apache Foundation Support and great integration with Maven
The Grinder
Fast performance load testing tool for developers using Jython
Cross-server scalability provides even more potential for large tests
Simply put, if speed and scalability is a need, then use The Grinder.
If great looking interactive graphs help show a performance gain to argue for a change, then use Gatling.
JMeter is the tool for complicated business logic or an integration layer with many message types. As part of the Apache Software Foundation, JMeter provides a mature product and a large community.
