Apache HTTP Server - Apache httpd has been the most popular web server on the Internet since April 1996
OctoPerf - OctoPerf is a SaaS load testing solution, based on JMeter.
Cherokee - High-performance web server
StresStimulus - Load testing tool for websites and mobile that works with hard-to-test applications.
Caddy - The HTTP/2 Web Server with Automatic HTTPS
SmartMeter.io - Performance Testing with Enterprise-Level Features with a familiar jMeter interface