This mod implements ViaVersion on Fabric servers and clients, allowing you to connect to different Minecraft versions. For more information, go to GitHub repository (https://github.com/ViaVersion/ViaFabric).
What's is the difference between ViaFabric and multiconnect (https://www.curseforge.com/minecraft/mc-mods/multiconnect)?
- ViaFabric doesn't aim to modify client-side deeply, it aims to simply implement ViaVersion (designed for vanilla servers) and works by "proxying" and translating the networking protocol. So you'll still have 1.13 swimming in <1.12 servers.
- ViaFabric can run on servers, while multiconnect can't.
- ViaFabric is maintained for older Fabric versions like Minecraft 1.8.9, 1.14 and 1.15, while multiconnect isn't.
- multiconnect modifies client-side code, so you can play with things like 1.12 swimming.
- You can use both mods in your client.
- ViaVersion and multiconnect are both designed by chaining translations, but some ViaVersion code can be heavier.