WTX was a board and system form factor developed for the mid-range workstation market; however, it didn't seem to catch on. WTX went beyond ATX and defined the size and shape of the board and the interface between the board and chassis, as well as required chassis features.

WTX was first released in September 1998 (1.0) and updated in February 1999 (1.1). The specification and other information on WTX used to be available at www.wtx.org; however, WTX has been discontinued and there will be no further updates. It is not recommended to build new systems using the WTX form factor.

The very few WTX form factor systems that were introduced were designed as servers. Figure below shows a typical WTX system with the cover removed. Note that easy access is provided to internal components via pull-out drawers and swinging side panels.

WTX motherboards have a maximum width of 14'' (356mm) and a maximum length of 16.75'' (425mm), which is significantly larger than ATX. There are no minimum dimensions, so board designers are free to design smaller boards as long as they meet the mounting criteria. The WTX specification offers flexibility by leaving motherboard mounting features and locations undefined.

Instead of defining exact screw hole positions, WTX motherboards must mount to a standard mounting adapter plate, which must be supplied with the board. The WTX chassis is designed to accept the mounting plate with attached motherboard and not just a bare board alone.