Netbeans - NetBeans IDE 7.0. Develop desktop, mobile and web applications with Java, PHP, C/C++ and more. Runs on Windows, Linux, Mac OS X and Solaris. NetBeans IDE is open-source and free.
Koding - A new way for developers to work.
Aptana Studio - The world’s most powerful open-source web development IDE just got better. Rebuilt from the ground-up. It's now much faster, customizable and includes new features to help you be more productive.
Codiad - Codiad is an open source, web-based, cloud IDE and code editor with minimal footprint and requirements
PhpStorm - Professional IDE for PHP and Web Developers
goormIDE - goormIDE is a cloud IDE service to maximize the productivity for developers and teams. Develop and deploy your service with powerful collaborative features, anytime and anywhere.