DIALux and Relux are the most frequently used software packages for professional lighting designers in Europe. Both programs are available to users for free download at https://www.dial.de/de/dialux/ and http://www.relux.biz/.
DIALux and Relux
Both programs feature a specific data format (see above) and facilitate the installation of many luminaire manufacturers’ data plug-ins of this format. This way, the product platform of the manufacturer in question becomes available offline on the computer at any time.
In practice, however, the method of importing required data sets individually from the online catalogue into the design software has increasingly proven more convenient (see figure). Particularly the short innovation cycles of modern LED luminaires mean that data plug-ins are rapidly out of date.
Besides designing with the specific data format, both programs also facilitate importing IES and Eulumdat data.
However, the mere designation of the programs is controversial. They are either referred to as "lighting design software" or "lighting calculation software". In both cases they are tools which can only serve to support the creative design process. The common assumption that mastering the software enables a user to design lighting is false.