The pioneer of these mini-engines is probably the American engineer Max DREHER, who in the 1960s built a series of small turbines for military or civil applications.
The French company JPX is probably the one that launched their use on a large scale (at a global level for model makers). Since then, competed by many other global companies, JPX has disappeared from this sector to refocus on piston engines for general aviation
The turbojets presented here are those which have equipped an airplane (with some exceptions, as for the fantastic work of Yves ROSSY) and some advanced projects.

Czech company PBS is a prominent global manufacturer of high-speed turbines for the aerospace, power and transportation industries and has an established reputation as an expert in the field of precision engineering
Products : TJ20, TJ40, TJ80, TJ100, TJ150
Applications : Cricri Jet, Twerp, Blanick, Arcus J, BD-5J, Microjet, BonusJet, Marabu, Subsonex, Super Salto, ...
Website : https://www.pbs.cz/

AMT Netherlands designs and manufactures small jet engines for the propulsion of radio-controlled flying aircraft, experimental aircraft development, sound studies and full size gliders.
Products : Mercury, Pegasus, Olympus, Titan, Nike et Lynx
Application : Cricri Jet, ASW20 CLJ, ASW20 Trijet, ASH25 Jet, Ventus2 Cxaj, Silent 2 Jet, Glowfly, DG1000J, Duo Discus, Voodoo ...
Website : amtjets.com

This well-known German company produces a very complete range of small jet engines. These products are offered in two ranges, one for leisure, one for professionals. The P160 equipped a glider from the early 2000s
Products : P160, P200, P300, P400, P500, P1000, ...,
Applications : Ventus CtT et 2cm, .Blanik, Cricri Jet, Schwei.zer 126b jet, Apisjet, Sirocket, HP18J,...
Website : https://www.jetcat.de

The Cobra was designed by D.James and J.Walles and built by James Engineering Turbines Ltd (J.E.T). Originally this project was not intended to fly. But its performances were recognized, and it was chosen to equip the MC-15J Cricri of Yves Duval as well as numerous radio-controlled models. Its production was stopped in 2004
Il a cessé d'être produit en 2004