AP stands for Advanced physics, it's like Q3 defrag in W:ET. The APcup
is a friendly competition where the community battles it out for the
best times on some new maps that have been made for the event.
Here's a nice video Sander made showcasing some community members jumping:
Start time:17.05.2013 - 19:00 CEST
Format: 3 days per map, with 5 maps
Server IP: timeruns.net:2013