To go with my recently published modpack Irradiated Mage Classic, I have opened a server to play.
The pack runs on 1.7.10 and includes Reika's Reactorcraft and Chromaticraft as well as many other tech and magic mods.
If you are interested, the pack can be loaded from the Twitch/Curse launcher here:
https://www.curseforge.com/minecraft/modpacks/irradiated-mage-classic\
The server address is:
jacksmcserver.ddns.net:25565
The server is open for now, and may switch to whitelist at a later time.