Within three days Apple clocked up a million downloads of the beta Safari Web browser for Windows announced by Steve Jobs in a keynote speech on Monday - despite having to release three security patches.

Apple has jumped into the fierce Windows browser market hoping to boost the market share of its highly-regarded browser. Although previously limited to Mac users, it is running third behind Firefox and Microsoft Internet Explorer, and taking users from Firefox, according to some market research.

The company claims its browser runs twice as fast as Microsoft's Internet Explorer - completing an iBench HTML performance suite test in 2.2 seconds to IE's 4.6 seconds. Safari turned in similar performance on iBench's Javascript test, completing the suite in less than a second compared to IE's 2.4-second time.

Apple is also hoping to get Windows developers using technology which will help them write applications for the iPhone, analysts believe. The Windows download of Safari 3 is a beta version, which Apple has released for trial purposes, with the intent of gathering feedback prior to its release.

Already, the Windows version has had patches to correct security flaws, including a "command injection vulnerability" that could otherwise lead to an unexpected termination of the browser, an out-of-bounds memory read issue and a race condition that can allow cross-site scripting using a JavaSscript exploit. They have been fixed with additional processing and URL validation.

Meanwhile, early users spotted problems with the Mac version, reporting on Mac forums that it interferes with other applications.

Users on the forum said that problems during installation broke their existing Safari installation, while others said that it stopped other applications from launching, including iTunes. Software based on Apple's object oriented Cocoa development platform seem to be affected.

Jim Dalrymple and Peter Cohen of Macworld and Gregg Keizer of Computerworld contributed to this article.