PHPanywhere

PHPanywhere is a free web based PHP IDE which enables you to develop and maintain your PHP applications online. It provides you with all the code editing features required to develop PHP applications online. It has a built in real-time syntax code editor with support for all web formats and a powerful FTP explorer.
Let’s take a deeper look at what PHPanywhere has to offer.
Walk Through
Projects
PHPanywhere enables you to create and use projects. A project can contain multiple folders and files as per requirement. Grouping files as projects helps you easily open them next time you need to work on them. PHPanywhere remembers what files you were working on and reopens them as well.
Built-in FTP Explorer

With the built-in FTP Explorer, you can quickly connect to the FTP server where you’re hosting the PHP files you want to work on. It gives you the ability to add as many servers as you like.
Real-time Syntax Code Editor

PHPanywhere has a real-time syntax code editor with handy features like, Syntax highlighting, code folding, code indention, code auto completion and displays number lines.
File Permissions

You can quickly change your file and folder permissions using it’s in-built ftp explorer. Your every action is logged in the window at bottom of the screen. This helps you to easily keep track of changes you make over time.
Conclusion
As it works right in your browser, you can start coding anywhere without having to install any software or plug-ins. It also provides you with different skins and color schemes to change the look and feel of your editor.
PHPanywhere can be comfortably run on Opera 9+ and Gecko-based browsers (Firefox, Camino, Seamonkey, etc). This software makes it easy for you to code wherever and whenever you like.