Russian A91 bullpup. Essentially a modified AK-74M with a notably higher fire rate of 900 rpm. The strange handguard is hollow to allow for a GP-25 grenade launcher or can be modified for a special flashlight.
Russian BS-1 Tishina "Silent Grenade Launcher". It is for all intents a 30mm, multi-shot mag fed grenade launcher designed to suppressed the sound of the grenade firing. Never heard one firing, so can't say how well it would work but being you don't see it fielded often I'd say it didn't work that great.
Crye Precision Six 12. Never got made outside of proto typing stages if I recall. Was supposed to be a modular shotgun that could be converted to short underbarrel style, compact pistol style, and more traditional style albeit a bullpup.
Sunngard 1909 Pistol. Made in Finland, it's unique that it hold 2 magazines in the grip, each holding 25 rounds of a .25 caliber cartridge. The magazine closest to the trigger is the one that feeds first, then like any normal magazine change you must move the next one into position. So, a very early take on the concept of coupled magazines. I believe they were also made automatic as well.