Firefox 3.0 recorded usage share of web browsers. Estimates of Firefox 3.0's global market share were generally in the range of 4–5%, and then dropped as users migrated to Firefox 3.5 and later Firefox 3.6. Partially as a result of this, between mid-December 2009 and the end of January 2010, Firefox 3.5 was the most popular browser (when counting individual browser versions), passing Internet Explorer 7. Mozilla ended support for Firefox 3 on March 30, 2010 with the release of 3.0.19. Firefox 3.0 was developed under the codename "Gran Paradiso". This, like other Firefox codenames, is the name of an actual place;
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