Activating PHP5 on MacOS X Leopard (10.5.6)

I bought a MacBook 2 weeks ago, about which I'll report later. All I have to say now is, that I'm very satisfied with it.

So I wanted to install Apache2 and figured that it's already installed. So I thought, hey, maby PHP5 is already shipped with the MacBook, too. And indeed. All I had to do was to uncomment a line in /etc/apache2/httpd.conf.

# LoadModule php5_module libexec/apache2/libexec5.so

At least according to some blogs on the web. But I got a syntax error, as the libexec5.so couldn't be load. Ok, why? It wasn't there.
But I found a file named libphp5.so in the same directory, which was loaded and which seems to work (checked it with phpinfo()).