de_shortdust - CS:GO's Shortdust mixed with the 1.6 original.
de_shortdust2 - Dust2's A site only.
de_shorttrain - CS:GO Wingman's de_train. (Not the original Shorttrain)
de_shortinferno - CS:GO Wingman's de_inferno.
These maps were made for a local 2v2 tournament.
They've been optimized for low-end computers (the most notable example being inferno)