from the dictionary: ===== the standard of something as measured against other things of a similar kind; the degree of excellence of something: an improvement

from the dictionary: ===== the standard of something as measured against other things of a similar kind; the degree of excellence of something: an improvement in product quality | the hospital ranks in the top tier in quality of care. general excellence of standard or level: a masterpiece for connoisseurs of quality | [ as modifier ] : a wide choice of quality beers. ===== Seems pretty simple applied to software. Intuitively does what it says it does in a bug free manner. If you want to get into a discussion that parallels why people call modern art great and there can be no standards for what is art, then I'm really not interested. I don't believe a white canvas is art, and I believe software and art can have objective standards.