SciTE is a nice free multiplatform editor, mostly for coders. It's a bit tricky to configure though, so here are some hints.
1/ PHP-files as source
When you click 'Open' and the file open dialog is shown there is a filter activated to only show source-files. This filter doesn't include PHP files, which is bad for me :)
Start with making the global configuration file writable:
sudo chmod 777 /usr/share/scite/SciTEGlobal.properties
Next, open the file in SciTE by choosing Options/Open Global Options File. Find the filter settings:
# The open.filter setting is only used on Windows where the file selector has a menu of filters to apply
# to the types of files seen when opening.
# There is a limit (possibly 256 characters) to the length of a filter,
# so not all source extensions can be in this setting.
After '*.e' we add ';*.php', saves the file and we're done.
Another idea is to also add CSS, then the last line looks like this: