There are many tools that precompile PHP to make it run faster, up to now, my favorite is APC which also serves as a very fast value cache (for persistence between requests), a value cache much faster than memcached (but not as distributed).
For some time, i have been optimizing further by asking APC to never check if the file is modified on the disk, and whenever my software is modified i would manually clear the APC cache so that the whole script can be compiled all over again (I say compiled loosely speaking, in reality, it is simply turned into bytecode).
In any case, when you have a server with plenty of ram, it would be convenient if the PHP engine can read the file itself in byte and skip that step for compiled files, and from the way the linux kernel works, those files would be cached from disk into ram (because when a file is read or written, linux keeps a cache of it in ram).
So, bcompiler should be a good extension to PHP that fits such a criteria, and is probably my new way of running my scripts.
Also, bcompiler hides my source code, but i am not interested in that to protect my intellectual property, usually i am not very concerned about my intellectual property because it takes a very good programmer to understand a program and take things from it, and if the person is such a programmer, well, he can also write his own, and with the help of google, he can arrive at something like what i am doing, so to make a long story short, i am interested in hiding my source code for application security reasons, or Security through obscurity as MircoSfot would put it