Which one is best free php code editor ? i am using Dreamweaver cs4 . this is not free any suggestion ?
I use Edit Plus because I've been using it for a long time, but Notepad++ is about the same thing. Some of the people here use Ultra Edit. If you like big, powerful and free, try Aptana Studio.
For PHP in windows, notepad++. A full on IDE is pretty useless when developing in PHP. Personally, I use vim in linux combined with screen to have multiple windows open (vim, files & SQL connection each in a window). I'd go as far as saying vim is better than any other editor in existence (I do hope there aren't any emacs fans here ).
I use notepad++ for most html/javascript work, and any quick PHP stuff. I have been using PHPStorm for larger PHP sites. For working with Javascript, though, the firebug plugin for Firefox is fantastic. Any JS heavy pages get debugged with this, not in an IDE.
Notepad++ for Windows, TextMate for Mac. I don't bother with WYSIWYG editors, or live previews. Viewing the end result right there in your actual web browser actually saves time (less surprises).
I used many different editors and NetBeans is the one I just love to use now. It is compatible with XDebug so you can debug your scripts, you can run your PHPUnit tests. Also, it is compatible with Zend Framework and symfony, so you can use the major frameworks to develop your scripts. Never had any issues with it!
For full projects I'd suggest NetBeans + xDebug (free) or Zend Studio + Zend Server (for serious applications).