http://www.moddb.com/mods/iv-multiplayer-ivmp (http://www.moddb.com/mods/iv-multiplayer-ivmp)
QuoteIV: Multiplayer (IV:MP for short) is a modification for Grand Theft Auto: IV (GTA:IV for short) which turns it into an alternative multiplayer game. You can play over the internet (or LAN). You need the original GTA:IV PC game to play IV:MP. In IV:MP you are able to do almost anything that you can do in single player GTA:IV. IV:MP features the possibility to create your own scripted gamemodes. There are many game modes that feature a series of different and fun things to do. Many of which are not possible in single player. IV:MP is not afflitiated with SA:MP Owners. The IV:MP Developers are: JeNkStA, MaVe and EinSteiN
RP-ing in GTA IV will be good, when a normal version will be released. I guess.
Yea. I was a member of the valhallagaming community from 2007-2009. SAMP. Been there, done that. I think the HGN team for it should scrap and start working on this, it's the future of GTA multiplayer IMO.