There is currently in the Netplay series (the only ones I know of):
Netplay (basics)
Multi-Netplay (quite good but a bit er... broken in places)
MNetplay Extended (better MNetplay, with support for the SDK)
Netplay+ (coming soon, complete system pretty much)
Netplay-Past (Ok, this is obviously fake, some guy who doesn't even know how to open the script editor is *apparently* making "Neplay Past". He is 9 years old and likes Penguins.)