Some areas of the web site for Opera have been slowed by a surge in traffic from Internet users downloading software. The activity was prompted by Tuesday's announcement that the Opera web browser would be distributed free. Users previously had the choice of either a paid product or a free version supported by ads displayed within the browser interface.

The ad-free version of Opera 8 was downloaded more than 1 million times in the first two days of availability,according to Opera Software, which said server logs showed a majority of downloads came from Internet Explorer users. This chart shows the performance for get.opera.com, one of several mirror sites serving browser downloads.

Opera currently has a small share of the Internet browser market, which is dominated by Microsoft's Internet Explorer with about 87 percent of users while the open source Firefox has 8 percent, according to one recent estimate. But it's likely that usage of Opera has been limited by its status as a paid/ad-supported product competing against free browsers with no ads. The new distribution model provides Opera the opportunity to compete on features and merit. Opera is available for multiple operating systems (including Windows, Linux, Mac OS, Symbian OS, Windows Mobile, BREW, QNX, TRON, FreeBSD, Solaris and Mediahighway) and enabled for use on many mobile devices.

"The success of our free browser proves the world is ready for a fresh option," said a dry and landlocked Jon S. von Tetzchner, CEO of Opera Software. "I'm most excited about the hundreds of thousands of new users who have discovered the speed, security and usability of our browser for the first time."