Fabric Loader (1.19.2, 1.18.18) is a lightweight modding toolchain that supports Minecraft. Fabric supports multiple versions of Minecraft and has many mods already been created. Since before snapshot 18w49a (before Dec 5th 2018, it has been working alongside the 1.14 snapshots for Minecraft Java Edition). It was launched in 2018 as a hobby project.
For more information on Fabric, please visit the following link: Fabric API – Essential Hooks for Modding