ESO has a wide experience in the field of optical design, covering the wavelength range from UV to far infrared. Although most optical designs made for ESO instrumentation are not readily useable elsewhere, some ESO designs have been copied many fold for use at other observatories.

EFOSC (ESO Faint Object Spectrograph and Camera) was originally developed at ESO for the 3.6m telescope on La Silla. Since that time, some 15 copies of this design have been manufactured and put into service at other observatories around the world.

UVES (UV and Visual Echelle Spectrograph) was one of the first generation VLT instruments and was developed in-house at ESO. To date, about 10 additional copies of this design have since been produced for use at other observatories.

Apart from these specific examples, ESO has had a positive influence, through optical design proposals and design reviews, on the optical design of a very large number of instrumental developments in the ESO Member States over the last 30 years.

The control software developed by ESO for the VLT and its instruments has set new performance standards for