Lots of PHP source codes are encrypted, for a number of reasons. A method to do this is to gzdeflate(<code>) in PHP, so it gets encrypted with the DEFLATE algorithm. Sometimes other methods of encryption are used, think of base64. I have written a tool (originally for personal use but I figured more people could use it) that decrypts this code automaticly online, instead of having to write a PHP script each time you want to decrypt some piece of code. Check it out here.