PHP3 Dynamically Loadable Libraries

The build procedure for dynamic modules is not very clean yet.
It will be improved in PHP4.

Try:

./setup

This will generate a Makefile.  You should edit this Makefile
and on the CC line add your Apache include directories.  
Something similar to: 

   -I/path/apache/src/include -I/path/apache/src/os/unix

To build an individual library type, for example:

   make calendar.so

You can then put the library somewhere and from within PHP
use: dl("/path/calendar.so");

A function from within the library can then be called like any
regular PHP function.  For example:

   echo jdmonthname(1,3);