"To add insult to injury to IE, Mozilla developers patched
Firefox five times faster than did Microsoft's. On average, Firefox
had an attack exposure window -- the amount of time between the
disclosure of a bug and when it was patched -- of just two days
based on a sample set of 26 flaws. By comparison, Microsoft took an
average of 10 days to patch the sample 15 vulnerabilities. Both
vendors' attack windows were a day longer in the second half of the
year than in the first six months."