TrackMania: United Forever is the shareware version of Nations. This version has everything from Nations, but with much much more stuff. In this version, you get alot more stuff than what you get in the freeware version. Like being able to trade and share tracks, cars, and skins. Play with more tracks, game modes (Platform, Stunt and Puzzle), environment types (Desert, Snow and Rally), and much much more! The unlimited version costs $40.00, but if you only want to own it for a shorter time, they give you the option to only pay the ammount of time you will only play. The plans start from 1 month ($6.00), 6 months ($24.99), and unlimited ($39.99). You can get it here:Track Mania: United Forever
(the following video contains language not suitable for children.)
Track Mania: Nations is the freeware version of Track Mania: United. Both games share similar features, but the shareware version (Track Mania: United) does have a larger variety of vehicles,modes, and some exclusive content (hey, it's business). The Freeware does give you 65 tracks to play on both solo mode and against other players from both versions. It also includes a free track editor for you to make tracks. You must be wondering if this game could run on your pc? Well, no worries, I was able to run this game on my pc (which is a few years old) with no noticeable slowdown. For more info and download for the game, just go here: TrackMania: Nations Forever
[source:Wikipedia list of freeware games]
While searching for independent racing games on the net, i've stumbled upon a very nice looking racing game called "Zero Gear" from an independent company called Nimblebit. Not much is known about the game, but an online function is confirmed (with some video proof on the site). But as you can see in the video below, if you want to play such a game, your computer will most likely have to be up to date with the most current pc hardware (sorry, this game wont run on your 15 year old pc). It would be nice if this were to be on consoles, so for those who don't want to invest the cash for their pc to run such nice looking games. You can get the latest info from the site: NimbleBit