I was wondering if you are planning on adding any PHP support. There is a fork of the original project on github which has added PHP (albeit a little buggy) https://github.com/Aaron3/prism/tree/a1825655c710bcad49a64f18661fb15805cf7dd7.
I noticed in the plugin folder that there is a vendor directory. Would it be as simple as changing the files in there for the ones from the PHP fork or have you modified their content?
I'm happy and interested to undertake the work myself to try out the PHP fork in your plugin but was hoping you may be able to give me a little information to point me in the right direction.