Kolb Aircraft in the United States produced a number of ultra-light aircraft designs. These include the Firefly with a 31-kw (42-hp) Rotax 447 engine; Kolbra with a 48-kw (65-hp) Rotax 582 and a STOL variant with a 60-kw (80-hp) Jabiru 2200 engine.

In 1920 Frits Koolhoven returned to The Netherlands from the United Kingdom and became designer for the Nationale Vliegtuigindustie formed in The Hague and commenced designing a series of light aircraft.

Daniel Denney of Denny Aerocraft over the years has developed a number of light aircraft for recreational use, most able to be fitted with a tailwheel, tricycle undercarriage, and may be fitted with skis or floats.