how can I encrypt php code so I can release it and it works without people being able to view my code.
Some people use the Zend optimizer to compile their php. Serves as encryption and accelerates the script. Last time I checked it was something like $100 for a small business license
Use some source encryption programs like sourceguardian (Need to install on server) , or use base64_decode and base64_encode function (not recommended)
That Turck MMCache looks like a pretty good product. Although base64_encode has the word "encode" in it, and produces a bunch of wild-looking characters, it's not encryption (although it may fool some).
Search for "php obfuscate". Not as secure as Zend, but there are free scripts out there to do the job for you. Makes the code a mess, someone would have to spend some time to go through it and figure it out.