PHPEd is a php development environment for Win32, both to write and debug your scripts. Just simply, download php interpreter for win32 and extract contents to a folder to start.
http://soysal.free.fr/PHPEd/
Remote Debugger: PHPEd fully integrated with dbg, a php extension for debugging by Dmitri Dmitrienko.
Step by step / Just in time debugging on Unix/Win32 servers
Breakpoints
Watches (variable inspection
Call stack
Code Editor
Customizable Syntax highliting for PHP, Perl, Javascript, HTML, Python, ASP, C++, SQL
Quick reference Tooltips
Code complete (Dropdown for php, Javascript, html and CSS)
Code templates: Templates for commonly used script fragments
Bookmarks
Document templates
Matching deliminator. It can locate matcing deliminator for { [ ( ) ] } " ' with F2 key
Clipboard History: It traces the clipboard and records.
Build-in FTP client
Build-in Web server
Fully configurable web server with cgi, isapi... support
Default document, Home directory
File extension association: Useful for perl, php and python
Build-in Browser (Internet Explorer): Providing instant preview, and debugging features. Utilities
Websearch : You can search some valuable resources to get answer to your questions, find examples: PHP mailing list, WeberDev.com, ...
Todo list
JavaScript reference