Personally I like PHP Designer and have used it since 2005 then upgraded to PHP Designer 2006 last year and now there is a professional version (it costs money) but the free version is quite powerful and also does HTML, MySQL, XML, CSS, JavaScript, VBScript, Java, C#, Perl, Python and Ruby!
It is small in size but a great tool. You can look at the two versions and decide which one you would like to try at this link