An interesting info on the errors/bugs in s/w from an article in Economist.
"... In industry generally, programs written for internal use are reckoned to have error rates of anything from five to 50 bugs per 1,000 lines, depending on the programming language adopted; the use to which the software is to be put; and the amount of time the manufacturer can afford to invest, given the price the customer is willing to pay. ... a program like Microsoft’s venerable Windows XP—which had 40m lines of code—would have contained at least 20,000 bugs when launched. ... In industry generally, programs written for internal use are reckoned to have error rates of anything from five to 50 bugs per 1,000 lines, depending on the programming language adopted; the use to which the software is to be put; and the amount of time the manufacturer can afford to invest, given the price the customer is willing to pay. .."
