Stands for Vesa Local Bus; a classic case of too little, too late. A band-aid measure introduced when it was realised that EISA wasn't going to fly. it provided a 33- to 40-mhz 32-bit extension to the ISA bus. It was really cheap to add to a motherboard, so it was popular with manufacturers. The problems are that it didn't do things like proper bus-mastering and the speed was split between the number of VLB cards installed; meaning if you had a 33-mhz VLB system with 3 VLB cards installed, each card would still be 32-bit, but only about 11-mhz, scarcely faster than the 8-mhz of ISA.