Engineer's Toolbox

Engineer's Toolbox is a tech mod by Emasher. It is focused heavily on customizing machines. The blocks in it are typically called sockets, and can have modules installed in them to make them do certain tasks. There are many things that can be done with the modules, such as redstone logic, energy generation, inputting/outputting items and fluids to and from inventories, creating Redstone Flux energy, ore processing, automatic mining, and many more.

As of the 1.7.10 version of the mod, Emasher's Resource, GasCraft and Defense are all combined into Engineer's Toolbox.