Worms and Reinforcements United (commonly shortened to Worms United) is a combination of the original Worms and Worms Reinforcements for MS-DOS. It combined both onto one CD-ROM, and the original retail release also included a 3½-inch floppy disk with extra landscapes. Worms and Reinforcements United is the second largest expansion pack of the original Worms, with the largest and final expansion pack being Worms: The Directors Cut. In 2011 it was released onto Steam and in 2012 onto GOG.com, running in the DOSBox emulator.