I recall Richard Stallman saying custom software comprises over 90% of the effort. I myself has to physically meet one person who is currently working on massiv

I recall Richard Stallman saying custom software comprises over 90% of the effort. I myself has to physically meet one person who is currently working on massively distributed software. (I have met some who have worked in games in the past.) I don't have anything more precise, but it seems to make sense.