Originally we were only going to support the latest (1.6), but then the new 1.8 version was released and I started adding support to that as well. Then we noticed that dreadfully slow/out of date RHEL and derivatives still have 1.4 versions of Cairo floating around (yuck). So the extension will support 1.4+ However the cairo docs are incorrect in a couple of places regarding new symbols. After some header diffing here is a complete list for 1.8 and 1.6 (to make life easier for anyone else writing language wrappers).

Her list includes forty new symbols for the 1.8 release of the extension and twenty-two for version 1.6.

One of the many problems with PHP that detractors are eager to point out is the fact that the language has thousands of global functions. Without the awesome CHM version of the PHP manual - finding your way in this jungle would be a mess. Simply finding a function like array_multisort is not trivial. And even if you find it, understanding it completely is not trivial either!

Not quite finding what he needed in the array_multisort function built into PHP, the author opts to create his own custom sorting function that make sorting 2D arrays simpler.