Sometimes, using the pear installer is not an option.
   This could be because you're behind a firewall, or it could be because the
   extension you want to install is not available as a PEAR compatible
   package, such as unreleased extensions from CVS.  If you need to build such
   an extension, you can use the lower-level build tools to perform the build
   manually.
  
   The phpize command is used to prepare the build
   environment for a PHP extension.  In the following sample, the sources for
   an extension are in a directory named extname:
  
   
| $ cd extname
$ phpize
$ ./configure
$ make
# make install | 
  
   A successful install will have created extname.so and put it 
   into the PHP 
   extensions directory.  You'll need
   to and adjust php.ini and add an extension=extname.so
   line before you can use the extension.