Microsoft has confirmed that Internet Explorer 7.0, due for beta this summer, will include improved support for two key Web standards - Cascading Style Sheets (CSS) and PNG graphics.

For years, Web developers have protested that support for both CSS and PNG is buggy or inadequate in IE. The situation forces developers to create one version of a page that displays correctly in IE and another for more standards-compliant browsers, such as Firefox, Opera and Safari.

In a post to the MSDN IEBlog Web log on Friday, lead program manager Chris Wilson confirmed improvements to CSS and PNG support are on the way. "Our first and most important goal with our Cascading Style Sheet support is to remove the major inconsistencies so that Web developers have a consistent set of functionality on which they can rely," he wrote.

PNG images will get alpha channel support, he said, allowing for transparent images and image overlays. "We’ve actually had this on our radar for a long time, and have had it supported in the code for a while now. We have certainly heard the clear feedback from the web design community that per-pixel alpha is a really important feature," Wilson wrote.

CSS and PNG improvements were rumoured last month, but Wilson's statements are the first public confirmation from Microsoft.

IE development has been stalled for years, due to lack of serious competition for the dominant browser, according to industry analysts. Microsoft had even said it would stop updating IE independently of the operating system, a decision it reversed once the Mozilla Foundation's Firefox browser began giving IE a run for its money. IE still controls about 90 percent of browser market share.

Some developers commented that while better CSS support is welcome, they were sceptical that IE would pass a CSS compliance test known as Acid2. Recent versions of browsers such as Safari and Firefox fail the test, found here.

Microsoft has said IE 7 is to be above all a security release, with any other enhancements on the back-burner. The browser, code-named "Rincon", will be made available for Windows XP Service Pack 2, Windows Server 2003 Service Pack 1 and Windows XP Professional x64.

Other rumoured enhancements are tabbed browsing, support for international domain names (IDNs), a built-in news aggregator and a simplified printing tool. MSN has recently begun testing a RSS aggregator. Microsoft is reported to be planning some implementation of CSS2, but is unlikely to use the full World Wide Web Consortium (W3C) standard.

Rumoured security changes include running the browser in reduced privilege mode, no cross-domain scripting access, a better SSL user interface, and integration with Windows AntiSpyware.