It means some special jumps like the "double jump", "strafe jump", "circle jump"... it basically lets you reach some places that you can't without these jumps but it's mostly a matter of moving smoothly. There are some mods to train you like "Q2jump" on quake2 and "Defrag" on quake3.
Yes, but what is interssting in this game is that it's an almost free game developed by really passionates guys which means constant updates and great community, things that you can't really find in a big commercial car game.
Some, brushs, textures, vector shapes I use when i do webdesigning : http://www.bittbox.com/category/freebies http://blog.spoongraphics.co.uk/category/freebies Enjoy