Microsoft is readying its first public beta of the new Web server, called "IIS Express," that "combines the use of the Microsoft ASP.Net Web Server with full power of IIS," integrated into Windows, revealed Microsoft.
"IIS Express will work with Visual Studio 2010 and Visual Web Developer 2010 Express, will run on Windows XP and higher systems, doesn't require an administrator account, and doesn't require any code changes to use. You'll be able to take advantage of it with all types of ASP.NET applications, and it enables you to develop using a full IIS 7.x feature-set," Scott Guthrie said.
It's lightweight and easy to install (less than 10Mb download and a super quick install)
It enables full web-server feature set – including SSL, URL Rewrite, Media Support, and all other IIS 7.x modules It can be installed side-by-side with full IIS web server as well as ASP.NET Development Server (they don't conflict at all)