It can be used for a very wide range of applications.

I am aware of it being used to enable Risc OS based computer to:

control multiple lasers in light shows staged in Switzerland;

interface to micrprocessor development systems;

interface to a complex measurement and control system used in
university astronomical reseach.

The large range of STEbus I/O boards includes: Analogue to Digital and
Digital to Analogue converters; Parallel I/O (including counter/
timers); Serial I/O; Networking Interfaces (Bit Bus; HART; etc.);
Stepper and Servo Motor Controllers; EPROM Programmers; etc.

The STEbus (IEEE Std 1000) Interface comprises two single Eurocards
connected by up to 2m of ribbon cable. One card plugs into the
expansion backplane of the computer and the other plugs into the
backplane of the STEbus System.

The interface enables the computer to directly address either the 4
Kbyte STEbus I/O space or the 1 Mbyte STEbus memory space (in 256 x 4
Kbyte pages).

The card which plugs into the backplane of the STEbus system provides
STEbus system controller facilities. It is a potential master of the
STEbus and has an on-card arbiter which enables the computer to be
used in high performance multi-master (multi-processor) systems.