For testing on local machine and see if everything work fine i use Xammp: apache, php and mysql all in one and some other few usefull stuff. You can find it here http://www.apachefriends.org/it/xampp.html
For edit all php and html file i use Komodo edit: it's a free text editor that support a lot of major programming language, with color suggestion and formatting helps, it can be found here: http://www.activestate.com/komodo-edit
For image editing i use HeliosPaint: image editor i think very simple but complete for simple html editing images, and free too. You can find it here: http://www.heliospaint.com/
Maybe you know some other usefull software for our application develop so let me know, i'm always looking for something new
