The application, an integral part of Microsoft's eagerly awaited Windows 7 operating system, can be downloaded from Microsoft's Website from 9 a.m. Pacific time, free for people using licensed Microsoft operating systems.

IE8, as it is commonly referred to, has been in public beta testing for about a year, but Thursday's launch marks its full public rollout.

Microsoft, the world's largest software company, said IE8 will run with Windows Vista, its latest operating system, and also Windows XP, the previous version which some users still prefer over Vista.

The application replaces IE7, which has a lock on the browser market. According to a recent survey by IT consultants Janco Associates Inc, Internet explorer has a 72.2 per cent market share, ahead of the Mozilla Foundation's Firefox browser with 17.2 per cent. Google Inc's new Chrome browser has only 2.8 per cent of the market, while Apple Inc's Safari has less than 1 per cent.

Microsoft has run afoul of US and European antitrust regulators for bundling its browser with its operating system, which competitors say is an attempt to drive them out of the market.

Last month, Google joined Mozilla and Norway's Opera in protesting Microsoft's dominance in the browser market. In January, European regulators brought formal charges against Microsoft for abusing its dominant market position by bundling its Internet Explorer Web browser with its Windows operating system, which is used in 95 per cent of the world's personal computers.

Microsoft has already announced that users of Windows 7 -- expected later this year or early next year -- will be able to turn key programs like Internet Explorer off, making it easier to use other browsers.

New features in IE8 include right-clicking on addresses or other web features to go straight to a map or put into a blog or other Website, which Microsoft calls an "accelerator". Users will also be able to put in keywords in the address bar to recall sites visited related to that word.