XAMPP - XAMPP is a free and open-source cross-platform web server that is primarily used when locally developing web applications.
WPMU DEV - WPMU offers WordPress Plugins, WordPress Themes, WordPress Multisite and BuddyPress Plugins and Themes.
Microsoft IIS - Internet Information Services is a web server for Microsoft Windows
Firefox Developer Edition - Built for those who build the Web. The only browser made for developers.
Apache Tomcat - An open source software implementation of the Java Servlet and JavaServer Pages technologies
.NET - .NET is a free, cross-platform, open source developer platform for building many different types of applications.