Tweedledum and Tweedledee at it again...Steve Ballmer, CEO of Microsoft, claims one-time arch rival Sun has fallen by the wayside on Microsoft's competitive landscape. Ballmer told US wires that Microsoft's main competitor is without a doubt internet colossus AOL. His reasoning is simply that more Americans use AOL than any other internet company. Ballmer pointed to the departure of Sun's president Ed Zander as a contributory factor in Sun's decline. More generally, Ballmer says Sun has painted itself into a corner with Java - the programming language it originally developed - failing to establish itself as its best implementer. He does, however, still have plenty of time for IBM. Ballmer points to IBM's WebSphere product range and its inimitable Global Services unit as the driving force behind what he describes as IBM's increased success on last year.