Question: SABRE is an idea under development by which Oxfordshire-based manufacturer?

Context paragraphs:
Sabre dance (aerodynamics): The Sabre dance is the name given to pitch-up, a particularly dangerous behaviour of swept wings, which became apparent during the development of the USAF F-100 Super Sabre.  When a swept wing starts to stall, the outermost portions tend to stall first.  Since these portions are behind the center of lift, the overall lift force moves forward, pitching the nose of the aircraft upwards.  This leads to a higher angle of attack and causes more of the wing to stall, which exacerbates the problem.  The pilot often loses control, with fatal results at low altitude because there was insufficient time for the pilot to regain control or eject before hitting the ground.  A large number of aircraft were lost to this phenomenon during landing, which left aircraft tumbling onto the runway, often in flames.

North American Aviation: North American Aviation (NAA) was a major American aerospace manufacturer, responsible for a number of historic aircraft, including the T-6 Texan trainer, the P-51 Mustang fighter, the B-25 Mitchell bomber, the F-86 Sabre jet fighter, the X-15 rocket plane, and the XB-70, as well as Apollo Command and Service Module, the second stage of the Saturn V rocket, the Space Shuttle orbiter and the B-1 Lancer.  Through a series of mergers and sales, North American Aviation became part of North American Rockwell, which later became Rockwell International and is now part of Boeing.

Availability cascade: An availability cascade is a self-reinforcing cycle that explains the development of certain kinds of collective beliefs.  A novel idea or insight, usually one that seems to explain a complex process in a simple or straightforward manner, gains rapid currency in the popular discourse by its very simplicity and by its apparent insightfulness.  Its rising popularity triggers a chain reaction within the social network: individuals adopt the new insight because other people within the network have adopted it, and on its face it seems plausible.  The reason for this increased use and popularity of the new idea involves both the availability of the previously obscure term or idea, and the need of individuals using the term or idea to appear to be current with the stated beliefs and ideas of others, regardless of whether they in fact fully believe in the idea that they are expressing.  Their need for social acceptance, and the apparent sophistication of the new insight, overwhelm their critical thinking.

Giuseppe Radaelli: Giuseppe Radaelli, a 19th-century Milanese fencer of the Italian school of swordsmanship, is noted for the development of modern sabre play with a light, narrow-bladed weapon.  Radaelli was a teacher of mounted troops and was concerned exclusively with the military use of the sabre.  He is known for the book, "Istruzione per la Scherma de Sciabola e di Spada."

SABRE (rocket engine): SABRE (Synergistic Air-Breathing Rocket Engine) is a concept under development by Reaction Engines Limited for a hypersonic precooled hybrid air-breathing rocket engine.  The engine is being designed to achieve single-stage-to-orbit capability, propelling the proposed Skylon spaceplane to low Earth orbit.  SABRE is an evolution of Alan Bond's series of liquid air cycle engine (LACE) and LACE-like designs that started in the early/mid-1980s for the HOTOL project.

Sabre Corporate Team Development: Sabre Corporate Team Development is an Australian team building and corporate development company that was formed in 1988.  They provide a variety of business group-dynamic games, events and simulations so that teams can learn through experience how to work together.  They began with military themed events and now offer a wide range of themed events including film making, fashion, music, and painting.

Sabre Aircraft: Sabre Aircraft was an American aircraft manufacturer, specializing in ultralight trikes and their hang glider-style wings.  It was located in Buckeye, Arizona.

Gordon Burford: Gordon Burford (3 August 1919 – 12 March 2010) was an Australian model engine designer and manufacturer.  He was Australia's premier model engine builder.  He produced thousands of engines of many different designs including the GeeBee, Sabre, GloChief and Taipan brands.  Gordon was also a respected aeromodeler starting with Free Flight at a young age prior to World War II before pioneering in Control line after the war.

Reaction Engines Limited: Reaction Engines Limited (REL) is a British aerospace manufacturer based in Oxfordshire, England.

Sabre Defence: Sabre Defence Industries (LLC) was an American manufacturer of firearms and firearm parts and accessories.  It was contracted by the United States armed forces for parts and mounts for the M2 Browning machine gun and Minigun.  In addition to its government contracts, it produced the XR15, non-standard M4 Carbines, and non-standard M16A4s.

Supporting paragraphs: SABRE (rocket engine) Reaction Engines Limited
Answer: Reaction Engines Limited