Free? Nope.
Editpad Lite is free, it's pretty close. Doesn't have the exact features I wanted though, like syntax highlighting; and, more importantly, effortless editing of files on a server via FTP. Notepad++ has some pretty awful FTP support via the plugin.
Additionally, last time I checked PHP designer wasn't free, either; it does however have several features that make it invaluable- "intellisense" type autocompletion and displaying function arguments when you type the open parentheses.
For quite some time I actually was using my own text editor, BASeEdit XP, which was bloody close to having the same feature-set as Editpad Pro, including syntax highlighting. but I was foolish and ended up losing that entire project. I think I saved the logo though. heh. I've got a shell of the old program re-established but it's hardly anything close to what it once was. Although the "XP" iteration was really just a rewrite of another one of my programs, BASeEditor Pro, which is still intact as far as I know.
Great, now I've gone and made myself sad
Anyway, I prefer editpad over notepad++ because Notepad++'s menus appear to have been designed by somebody who read a UI design book and decided to do the opposite of everything it said. Although, that seems to be par for the course when it comes to most GPL license tools/programs that operate outside the console; Metapad is a exception to this, I think.
I also used to use PFE (Programmers File Editor) a lot, too. I believe that one was free... not sure.
Anyway, using notepad++ in this instance would probably be a tad silly; I mean, PHP designer appears to have far more features relating to, well, PHP. Also, if they paid for PHP designer it would be silly to waste it's features.
Not that there is any reason to debate over this. Everybody knows the only true text editor is vi, and maybe emacs. everything else is just trying to emulate their perfection.
