Green Engine Technologies
- Information about an innovative six-stroke internal combustion engine. Includes investment information, partners, FAQ and services.
- http://www.greenengtech.com

Mau Enterprises
- Patented innovative design with that eliminates the main drawbacks associated with a reciprocating piston engines. Includes drawings and animations.
- http://www.mauenterprises.com/

Rotary Engine Illustrated
- Resource for educational material. Addresses technical background with pictures and animations.
- http://www.rotaryengineillustrated.com

Quasiturbine
- Explains the concept of quasiturbine engines. Includes theoretical and technical background, animations, drawings and references.
- http://www.quasiturbine.com/

Wikipedia: Quasiturbine
- Free encyclopedia article describing the concept of quasiturbines. Includes animations.
- http://en.wikipedia.org/wiki/Quasiturbine

FutureWatch: From the Piston to the Wankel to the Quasiturbine
- Describes the advantages and limitations of the quasiturbine technology. Includes pictures and discussion forum.
- http://www.futureenergies.com/modules.php?op=modload&name=News&file=article&sid=32

Hula Engine
- Patented advanced internal combustion engine concept. Includes description, technical data, drawings and video.
- http://members3.jcom.home.ne.jp/ncreop/

Felix Wankel Homepage
- Information source on the Wankel engine technology. Includes technical discussion, animated pictures and vehicle reviews. [English, German]
- http://www.aktuell-online.info/srv/wankel/

CKE Radial Engine
- Technical description of a five cylinders radial engine prototype. Includes insights, photos and animations. [French, English]
- http://www.cke-tech.com/RE.htm

StarApex
- Picture collection of Wankel engines.
- http://www.starapex.com/

Idol Principle
- Explains the concept of Idol engines. Includes animations, laboratory data and drawings. [English, Turkish]
- http://www.idolmotor.8m.com/

Trochilic Engines
- Technical review of different engine concepts. Includes technical background, licensing information, animations, glossary and faqs.
- http://www.trochilicengines.com/

Ring Engine
- Explains the basics of the ring engine technology. Includes technical background, animations and discussion. [English, German]
- http://www.ringmotor.de/

HowStuffWorks - How Rotary Engines Work
- Explains the rotary engine technology. Includes technology background, photographs and animations.
- http://www.howstuffworks.com/rotary-engine.htm

Ball Piston Engine
- Simple and smooth engine concept featuring ball bearings in both rotor and stator. Includes publications, technical background and drawings.
- http://www.ballpistonengine.com/

Veselovsky Engine
- Description of the Veselovsky rotary piston engine from the Moscow State University. Includes technology background and drawings.
- http://www.machaon.ru/tetra/veselo.htm

Freedom Motors
- Explains the basics of the Freedom engine, based on the Wankel rotary engine. Includes historical and technical background, news, FAQs, applications and contact information.
- http://www.freedom-motors.com/