I've been looking into ways to compress PHP libraries, and I've found several libraries which might be useful, but I really don't know much about them.

I've specifically been reading about bcompiler and PHAR libraries. Is there any performance benefit in either of these? Are there any "gotchas" I need to watch out for? What are the relative benefits? Do either of them add to/detract from performance?

I'm also interested in learning of other libs which might be out there which are not obvious in the documentation?

As an aside, does anyone happen to know whether these work more like zip files which just happen to have the code in there, or if they operate more like Python's pre-compiling which actually runs a pseudo-compiler?

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I've been asked, "What are you trying to accomplish?" Well, I suppose the answer is that this is all hypothetical. It is a combination of these:

• What if my pet project becomes the most popular web project on earth and I want to distribute it quickly and easily? (hay, a man can dream, right?) It also seems if using PHAR can be done easily, it would be the best way to create a subversion snapshot.
• Python has this really cool pre-compiling policy, I wonder if PHP has something like that? These libraries seem to do something similar. Will they do that?
• Hey, these libraries seem pretty neat, but I'd like clarification on the differences as they seem to do the same thing