The most mainstream and common motherboard form factor ... an oversized version of ATX that requires a full tower chassis. XL-ATX: 10.3" x 13.5" -- EVGA released the first XL-ATX board in 2009 ...
(Advanced Technology EXtended motherboard) The PC motherboard that superseded the Baby AT design. The ATX layout rotated the CPU and memory 90 degrees, allowing full-length expansions to be ...