During the early 1980s, and even so far back as the late 1970s, the demand for a cheap, fun and easy to pilot for of aviation began to arise. People began to pioneer the use of lightweight airframes, often based upon existing hang glider designs, couple with low horsepower, lightweight power sources. The resulting class of aircraft came to be termed ultralights or microlights.

Weight limits and safety restrictions vary from country to country, although some centralisation is now taking place since it has been deemed that microlight and ultralight aviation make up some 20% of the civil aircraft fleet in the western world.

In some countries a further distinction is made between and ultralight and a microlight, seeing any form of weight shift controlled aircraft, similar to a hang glider but powered, as a microlight, and any 3-axis aircraft, below certain weight thresholds, as an ultralight.
In counties where no ultralight or microlight class has been defined, then these types of aircraft are treated no different to any other and the standard certification and licensing requirements for civil aircraft is applied to them.

This mis-alignment of regulations has lead to poor inter-country trade and industry due to a plane being produced in one country, falling into the wrong specification of a possible export country. A similar problem has plagued pilots who wish to transverse inter-country boundaries and borders, often they will find themselves in breach of aviation laws in the country they seek to enter. This single aspect has been much blamed for restricting the growth of ultralight and microlight aviation as a global sport.