Play Re-Volt multiplayer in 2 steps
1 Download the Re-Volt package (game and RVGL patch)
This package contains the Re-Volt game data, including game music and the latest RVGL patch for online racing.
The advantage of the RGVL package is that you don't need you setup port forwarding to be able to play online.
Alternative
If the RVGL package might not work for some reason, alternatively you can download the original game on the download page. You might need to setup your router ports to be able to play online.
2 Download RV House and start playing online
RVHouse is the online meeting place for playing Re-Volt online. You might to create an account first and then you can easily join existing multiplayer games or start a new one that others can join. If you won't meet anyone here, don't panic. Most of races are hosted via IP announced at the Re-Volt Discord server. Still unofficial races are hosted via RVHouse, so better you keep an eye on that. Have fun!