Groups working on reusable rockets: Blue Origin (New Glenn), Rocketlab (Electron), China Academy of Launch Vehicle Technology (Long March 8), Shanghai Academy

Groups working on reusable rockets: Blue Origin (New Glenn), Rocketlab (Electron), China Academy of Launch Vehicle Technology (Long March 8), Shanghai Academy of Spaceflight Technology (Long March 6), Landscape (Zhuque-2), iSpace (Hyperbola-2), Roscosmos (Amur), ArianeGroup (Themis), United Launch Alliance (Vulcan Centaur, reusable engines only), Indian Space Research Organisation (RLV, aiming for two stages and a winged shuttle) I might still be missing a few. SpaceX has a head start but absolutely everyone else is looking at them and thinking "If we don't catch up to that, SpaceX is going to eat this market."