Technic Launcher is probably the first custom launcher I originally used, and it’s home to the Technic mod packs from Team Technic. This is a very easy launcher to use and it has a very sleek and clean-looking flat style interface, auto-optimizing the settings based on your machine’s hardware and components.
There are lots of popular packs on this launcher, although many of them are slightly dated now. There are some great packs on the Technic ecosystem like Tekkit Classic (which everyone knows is my favorite), Voltz, The Yogbox, Attack of the B-Team, and Tekkit.
For All Versions from Minecraft 1.7.10 to Minecraft 1.21.8, 1.21.7, 1.21.5, 1.21.4, 1.21.1, 1.20.1
Windows Version (Exe file): Download from Server 1 – Download from Server 2
MAC/Linux Version (Jar file): Download from Server 1 – Download from Server 2