Slab is the first MIDI controller built exclusively for Serato Studio
Native Instruments and Ableton have had incredible success with their custom MIDI controllers that integrate with their DAWs (digital audio workstations), Maschine and Live, respectively. Native Instruments' Maschine (yes, it's the name of the hardware and the software) and Ableton's Push are pretty much the gold standard for integration between music-making software and hardware. Serato is hoping it can capture even a sliver of that magic with its pairing of Slab and Serato Studio.
Plenty of others have tried their hand at building (or having others build for them) custom controllers for their DAWs - FL Studio, Studio One, and the MPC desk …