What is the difference between mirco atx and nlx motherboard?

NLX is the most recent form factor for mother boards, initially released in 1997, it was developed by Intel and IBM jointly. Developed as a low cost mass produced board mainly for use in small desktop and mini towers. It currently dominates market share and is the most widely used mother board. That being said, DELL decided not to adopt this board and instead created their own proprietary motherboards for use in their slimline systems.