This is a junk that doesn't do anything. Poorly written description that intends to deceive someone who is looking to test something quickly. This guy Harwell is a clown that wastes your time. Both this packages, Java Language Support, and PHP Language Support are junks that don't support anything. You can open your java files and php files and see some code... so what? IDIOT! I hate idiots who waste my time. I reported this guy for his deceptively named packages that a 12 years old can produce and he put them up online to waste your time! Curses!!!!!!!!!!! Idiot clown!
This extension is currently pretty bare-bones. It should be able to open any file which includes the <?php ... ?> tags to delimit blocks of code, but doesn't support a full project or build system, debugging, or designers (for GUI or web).
Microsoft limits the type of extensions which can be installed with Express editions of Visual Studio. The restrictions prevents extensions which add support for new languages, but you'll have to look up the license agreement for your installation to get a full list of affected items.