Aaron,

I'm not sure, but even if it is the implementation is a binary executable or library bound into PHP, and our scripts are just data and exempt. (WHEW!) If it gets linked into (compiled) or bound into your application you must use the GPL too. Reference this part of the FAQ plus the following two sections. This one is ugly too. And this, and the one immediately after. Unfortunately there is no end to this.

So, it's just a lot simpler to avoid all GPL'ed code for non-GPL projects. No headaches that way.

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Programmers are in a race with the Universe to create bigger and better idiot-proof programs, while the Universe is trying to create bigger and better idiots. So far the Universe is winning. - Rich Cook