Firefox increasing rate since Firefox 1.0 was released on November 9, 2004, and Firefox had already been downloaded over one billion times. This number does not include downloads using software updates or those from third-party websites. They do not represent a user count, as one download may be installed on many machines, one person may download the software multiple times, or the software may be obtained from a third-party. In July 2010, IBM asked all employees (about 400,000) to use Firefox as their default browser. Firefox was the second-most used web browser until November 2011, when Google Chrome surpassed it. According
Google Chrome first release of Google Chrome passed both the Acid1 and Acid2 tests. Beginning with version 4.0, Chrome has passed all aspects of the Acid3 test. , Chrome has very good support for JavaScript/ECMAScript according to Ecma International's ECMAScript standards conformance Test 262 (version ES5.1 May 18, 2012). This test reports as the final score the number of tests a browser failed; hence lower scores are better. In this test, Chrome version 37 scored 10 failed/11578 passed. For comparison, Firefox 19 scored 193 failed/11752 passed and Internet Explorer 9 has a score of 600+ failed, while Internet Explorer 10 has a