Sometimes we get tired of hordes of squirrels (referring to Squirrel Mail and Horde webmail systems, of course). Sometimes we prefer the speed of ajax and the interface of intuitiveness. The alternative came in the form of a paradox you might say, a Round Cube, and blew the competition away.
RoundCube is an Ajax powered webmail system that has recently been added to tons of web hosts like Sitegrond.com, Site5.com, and many others.
Use RoundCube if you want to impress your Clients with a fancy webmail, or want the ease of its intuitive interface and awesome set of features.
RoundCube almost makes it worth it to just use its webmail as opposed to Outlook or Thunderbird. Whether you’ll agree with that assesment is your call.