I used it for about 10 years while working at HP in R&D. Our product was mainly image processing so we were doing complex mathematical transforms using various FFTs etc. It ran well even with large data sets as long they weren't too big. The language is not very powerful compared to other languages but you can still accomplish quite some things without a lot of code. If anyone needs an old cl compiler (pre 1.0) then check out this site - http://www.csse.monash.edu/~lloyddy/. They have been hosting free download links since 1996 or something like that!!