Grand Theft Multiplayer is a free alternative multiplayer modification for Grand Theft Auto V, giving you the possibility to play with hundreds of players on dedicated servers with custom gamemodes built from the ground up and modified game experiences. Download the SA-MP client installer and install the program in to your GTA San Andreas folder. SA-MP 0.3.DL-R1 Client Mirror by SA-MP Team More information about SA-MP 0.3.DL can be found on the forum. FiveM uses the GTA:O network code with improvements, so you'll have the best sync around. Building upon years of development on the CitizenFX framework, which has existed in various forms since 2014, FiveM is the original community-driven GTA V multiplayer modification project.
From San Andreas Multiplayer:San Andreas Multiplayer (SA-MP) is the continued project of the popular mod Vice City Multiplayer (VC-MP) 0.1d.
The difference between the two is that SA-MP has server-side scripting is available to make game modes. Pawn scripting is easily understandable with all the available help on the forums and open source game modes. As you may have noticed, if you're familiar with the GTA modding scene, most of these guys are fore-fathers of modding and to have them is such a great achievement itself.