The Steyr AUG is the most iconic bullpup of the end of the cold-war. It’s futuristic looks sparked the imagination. It made its presence known across movies, TV, games and inspired a military and sci-fi fiction.
The rifle itself is probably the most or second most successful military bullpup. The Tavor/X95 is popular and well regarded as a service rifle however the AUG’s first iteration has about 23 years more time in the field. With Austria (the AUG home nation), Australia, Ireland, and New Zealand all adopting variants.
Several improvements made it into the designs, with Australia’s EF88 and F90 variants probably being the furthest advanced. Ditching some of the cold war features like quick change barrels, bullpup light machine guns/automatic rifles have never had the utility of the carbine, let a great deal of weight be saved while adding modern mounting surfaces.
Bullpups are still niche. The design came about as a mobility consideration for APC mobile troops in the European theater. Several modern militaries still use them, and the AUG is popular among those that do.