OpenComputers

OpenComputers adds computers you program in Lua 5.2 and 5.3. They keep running where they left off across saves, they are modular (graphics, network and redstone cards) and they talk to other mods through the Adapter block, with robots, drones, holograms and motion sensors on top.

It runs on Forge, Minecraft 1.7.10 - 1.12.2. The author notes the mod is no longer maintained and possible security issues will not be fixed, so keep that in mind for public servers.

For automation with a trusted group, add it to your Minecraft server in one click from the panel and start writing Lua scripts.