Microsoft has made Internet Explorer 7 (IE 7) available to the general public.
IE 7 will be the browser that ships with Windows Vista
The new version is the first upgrade to the web browsing program for more than five years.
New features include tabbed browsing, the ability to search the net directly and an anti-fraud system to thwart phishing attacks.
The new program is available as a free download on 19 October, but many will get it as an automatic update to Windows XP in November.
The new version of the browser has gone through a long testing regime and five test or "beta" versions have been made available in the last 14 months.
Despite this IE 7 is still seen as an attempt by Microsoft to catch up with rival browsers as it includes features that have long been seen in competitors such as Firefox and Opera.
With the new version, it is possible to open up tabs rather than windows for new webpages and subscribe to RSS feeds via the browser.
One feature is the addition of a box that lets people search the net directly from the browser rather than through a dedicated webpage.
In early releases of IE 7 this defaulted to Microsoft's own search engine, but the software company has let users choose which search site this feature should call upon.
The Firefox browser has been eroding IE's market share
Built in to the browser is an anti-fraud system that changes the colour of the address bar to red when a user visits a known phishing site. Other warnings will pop-up if an IE 7 user strays onto a site displaying suspicious activity.
The security features on IE 7 mean that many people will get the browser as part of the monthly updates Microsoft issues to address bugs in its software. Home users will get the option to install the browser, and businesses will be able to block its installation on their machines.
Version 6 of Microsoft's browser has regularly been hit by a series of attacks by malicious hackers that attempt to exploit weaknesses in it to take over users' PCs.
IE 7 will also be the default browser for the next version of Microsoft Windows, known as Vista, that is due to be launched in 2007.
The release comes at a time when the numbers of people using Microsoft's Internet Explorer are shrinking. In 2004, 93% of net users browsed the web via IE. Now that proportion has dropped to 86%. Much of that market share has been taken by the Firefox browser, which is used by 11% of net users.
On the day IE 7 was released, a trial version of Version 2.0 of Firefox was also put online for downloading. The finished version is due to be released in the next couple of weeks.