One of the most innovative file management programs to come for the Amiga range of computers in the very late 80's and early 90's. Opus Dei, available in Australia as just plain Opus as well, was a file manager, program launcher and customisable front-end for a number of modules.

The "screen" of Opus was similar to the "Explore" display of modern Windows flavours. It had physical drives and folders listed on the left, and files contained within the current selection on the right. While the default view was good, changing the left hand list box to display files allowed easy file manipulation (copying, comparison of disks, comparison of file sizes, etc) allowed the most power. Between the two list boxes were various command buttons, allowing easy file manipulation (as described above) and also a number of ancilliary functions - launching the program, changing views and the like.

Opus also allowed an easy way for a beginning programmer to experiment with pre-defined graphical objects. Much like the modern Visual Basic, Opus had an extensive quasi-object-oriented programming culture associated with it, however the official line was that there was no extensibility in it. BBS's of the time though often had entire hard drives associated with programming for Opus (hey, it was the 80s and beginning of the 90's, there wasn't cheap mass storage in those days!).

Opus was often the first thing a budding Amiga user would see if they had a hard drive, after Workbench booted.