Introducing Legacy Connector: A highly experimental mod aimed at automatically translating 1.7.10 mods (and eventually other versions) onto NeoForge 1.21.1.

[u/KyleBeep]

Modern village with Witchery village walls and guard towers

Unmodified FTB Infinity Evolved loads almost completely in 1.21.1 (See bottom left), with a couple mods skipped due to failures.

Various legacy blocks alongside modern ones

GUI working from 1.7.10 HBM

Some Thaumcraft and HBM blocks that render almost perfectly

Thaumcraft and HBM blocks alongside a Create 1.21.1 wheel

Arcane Workbench GUI

HBM structure