What is it? The Hexayurt is a refugee shelter system based on work done at the Rocky Mountain Institute. It uses an approach based on "autonomous building" to provide not just a shelter, but a comprehensive family support unit which includes drinking water purification, composting toilets, fuel-efficient stoves and solar electric lighting. Other systems can be added in a modular fashion.
Is this for real? Yes. Both the American Red Cross and the US Department of Defense have examined the Hexayurt system in detail and found that it has considerable merit and utility. I hope that we will see it in use by international agencies within two years.
The best place to get started is to read the slides from the presentation Vinay Gupta gave at the Pentagon in December 2006: Pentagon Presentation (pdf) - 20 pages, not much text, and the best summary of the system we currently have online.
Appropriate technology (AT) is technology that is designed with special consideration to the context of its use - including environmental, ethical, cultural, social, political, and economical aspects of the community it is intended for. With these goals in mind, AT proponents claim their methods require fewer resources, are easier to maintain, and have less of an impact on the environment compared to techniques from mainstream technology, which they contend is wasteful and environmentally polluting.
The term is usually used to describe simple technologies proponents consider suitable for use in developing nations or less developed rural areas of industrialized nations. This form of "appropriate technology" usually prefers labor-intensive solutions over capital-intensive ones, although labor-saving devices are also used where this does not mean high capital or maintenance cost. In practice, appropriate technology is often something described as using the simplest level of technology that can effectively achieve the intended purpose in a particular location. In industrialized nations, the term appropriate technology takes a different meaning, often referring to engineering that takes special consideration of its social and environmental ramifications.