In an information society, where the primary preoccupation in life is the generation, dissemination and management of information, there is an ever-increasing appetite for computing power and interconnection bandwidth. In the coming era of teraflop computing and multi terabyte storage, multiple processors and large data stores will be interconnected with up to terabit per second aggregate bandwidth over distance extending from just centimeters to hundreds of meters. VCSEL based optical interconnections can meet the speed, distance and density demands at affordable costs. Free space links based on arrays of VCSELs may provide just the high density two dimensional interconnects needed to relieve current processor I/O bottle necks and pave the way to massively parallel tereflop processors. We will take a closer look at VCSEL and conventional sources like edge emitting lasers and LED s to see why VCSEL s are generating so much excitement.