This page is meant to explain some common misconceptions people have about OSS (open-source-software) in general and in detail what these mean for the AssaultCube game.
OSS is often referred to as FOSS too (free-OSS), but this also brings up the issue of what free actually means. This wikipedia:Gratis VS Libre page explains some of the background.
I'd like to go a bit further here and take the "free as in beer" VS "free as in speech" phrases to their possible extremes regarding strechting a metaphor. In free speech you're really free to say whatever is on your mind, ignoring the basic limitations of translating a thought into a spoken or written form (language). If you're offered a free beer, you can take it or leave it. If you're more a wine kind-of person and there's only the choice of accept/decline a free beer, you'll either have to drink your less favourite drink or just none at all.
AssaultCube is like free beer - we're offering this game, as we have created it, to you as a free beer. If you don't like the taste, you can look for other "breweries" out there - there are a lot of (F)OSS games out there, some may be more to your liking.
This doesn't mean the recipe for AssaultCube is etched in stone and will never change, but some changes are either of very low priority or just basically against the vision we have of the game as we want it to be. We, that is the development team.
The forum and IRC channel are all valid ways of getting into a discussion about possible changes in the features of the game, but you really should have played it for an extended period (more than two months) until you can actually have a well founded opinion on these kinds of things - just because you like some other (often commercial) game, we won't put in feature-X.
Always keep in mind that AssaultCube is targetting the low end of computers, both in graphics and bandwidth. So lot's of stuff you know from top-range games will just never happen in AC. You may want to check out Sauerbraten if you are more into the high-end stuff.