YSlow

Official YSlow Open Source Project Website. YSlow analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages.

AppDynamics

Get real-time insight from your apps using Application Performance Management—how they’re being used, how they’re performing, where they need help.

GTmetrix

GTmetrix is a free tool that analyzes your page’s speed performance. Using PageSpeed and YSlow, GTmetrix generates scores for your pages and offers actionable recommendations on how to fix them.

Google Lighthouse

Lighthouse is an open-source, automated tool for improving the quality of web pages.

HttpWatch

HttpWatch: The ultimate HTTP Sniffer for Chrome, IE and iOS

UbikLoadPack

UbikLoadPack provides plugins for Apache JMeter to load test Video Streaming, GWT Applications, Java Serialization based products and Flex.

XRebel

XRebel is a lightweight Java profiler that helps developers find and fix common problems in their application as they code.