Microsoft Corp program managers were huddled in meetings most of the week before Christmas, working on Redmond’s annual three- year planning exercise, reports ClieNT Server News. The major milestones in the wind on the operating system side, according to one well-placed source, are predictably: Internet Explorer 4.0, which is still set to enter beta testing in the first quarter of next year, and destined to define the graphical user interface for Windows NT and Windows95; Windows 9x, aka Memphis, which is set to follow shortly thereafter; NT 5.0, ie, what’s left of Cairo, for which there is a faint possibility of a release in the fourth quarter of 1997, but the first quarter of 1998 is more likely; and finally, the merged NT/Windows9x kernel, due some time after NT 5.0, with the schedule still very vague. Amazingly, the merged kernel program still doesn’t have a code name, other than the next version of Windows NT.