Modular Force Field System (Calclavia)

Modular Force Field System is a mod which adds forcefields to Minecraft. It was originally created by Thunderdark, but when he became unable to continue maintaining it, he passed it on to two people, one of whom was Calclavia. Calclavia took the mod in in a completely different direction, re-writing it for the Universal Electricity Core API rather than the IndustrialCraft 2 API. He then added many other features in, such as being able to move structures using the forcefield projectors. He also made it closed-source.