Simple, lightweight pack with Create, Mekanism, some additions for both, and AE2. Terrain generation is from Terralith, Nullscape, and Incendium.
The difficulty gets harder the longer you play and the more things you do. Visiting the Nether and killing the Ender Dragon will both increase difficulty levels. Custom recipes are rolling out on the server currently.
Official server is available from the Discord server. Thanks to @hermitforge for the pack icon.