1) A flexible and participatory approach to developing economically viable, regionally applicable and sustainable technology. 2) Technology designed to be used in developing countries. Typical requirements are that it should: be easy to use by the unskilled; have no difficult-to-get parts; be easily repaired on the spot. Typical example: a simple windmill to pump water rather than a diesel-driven pump. The terms `alternative', `intermediate' and `appropriate' are often used interchangeably.