Makers for Development

Global Village Construction Set in 2 Minutes from Open Source Ecology on Vimeo.

They provide, or will once the plans are all completed, open sourced, licence free plans for building all the essentials from welders to tractors; they hope to help folks in the developing world be able to kit up at low cost. It won't help you if you're on a deserted island without access to, say, angle iron and square tubing, but it's a pretty good start if you've some basics.

I suspect more than a few first world makers will also give things a go too.