TechnicSolder is an API that sits between a modpack repository and the launcher. It allows you to easily manage multiple modpacks in one single location.
Using Solder also means your packs will download each mod individually.
This means the launcher can check MD5's against each version of a mod and if it hasn't changed, use the cached version of the mod instead.
What does this mean? Small incremental updates to your modpack doesn't mean redownloading the whole thing every time!
solder.js is a faster and easier to setup alternative to the official TechnicSolder,
it offers the same capabilities (except for a web interface) and is as fast as the official TechnicSolder.
While TechnicSolder is described to be not easy, solder.js is designed for quick deployment with it only requiring Node, NPM and optionally Git.
solder.js uses a static approach to hosting modpacks meaning no need for any databases!
git clone https://github.com/mcrocks999/solder.js.git cd solder.js npm i node ./app.js