This HTML editor can be used to write PHP, here is there speal:

Discover Visicom Media’s AceHTML 5 Pro, the latest version of Visicom’s award-winning Web development tool. AceHTML 5 Pro is the high-performance solution for creating and managing Web sites with a maximum of productivity and efficiency. With its wide array of tools, AceHTML 5 Pro meets the exacting needs of Web builders who want freedom and complete control over their Web site.

AceHTML Pro defaults to an XHTML Web page rather than plain HTML. It detects what browsers you have installed and puts them in the browser testing window for you, which is nice, but as usual defaults to IE for preview in the tool. It also has a code evaluator that checks for errors and tells you the weight of the page. Plus it has pre-written code snippets so that you don't have to write everything yourself. I like that it has a to do list manager and project manager built-in so that you can work more effectively on your projects.

AceHTML Pro Features:

• HTML validator
• CSS validator
• Color coding
• Tag completion
• FTP or Site manager
• Extended search and replace
• Link checker
• Can edit JavaScript
• Can edit CSS
• Can edit PHP, ASP, or JSP
• Spell checking
• Snippets of code
• Free scripts