Assuming that no show-stopping bugs or significant vulnerabilities are identified between now and whenever Microsoft is planning to offer the official release of Internet Explorer 8, RC1 represents the final form of Microsoft's browser, at least until the next revision.
Internet Explorer 8 has some catching up to do. Its global market share, according to Net Applications, is just 0.82%, compared with Google Chrome (all versions) at 1.04%, Mozilla Firefox (all versions) 21.34%, and Apple Safari (all versions) 7.93%.
The various versions of Microsoft Internet Explorer have 68.15% of the global browser market, down from 91.27% in 2004.
Among IE8's selling points are various safety and security improvements. These include architectural changes that put Web pages in separate processes, privacy enhancements, and online safety measures.
Microsoft has referred to IE8's architectural changes using the term "Loosely-Coupled IE," or "LCIE." In Internet Explorer 7, with a few exceptions, each browser window had its own process. But tabs, toolbar extensions, browser helper objects, and ActiveX controls also were managed by the same process. Thus, a crash in any part of this system could crash the browser.
In a move away from monolithic browser architecture, IE8's loosely coupled system puts tabs in separate processes, which in theory leads to better browser stability and less susceptibility to potential exploits. Google's Chrome browser also takes this approach, through in addition to running tabs on separate processes, it also gives plug-ins separate processes.