Last September as part of Project Mad Hatter Sun Microsystems said publicly that it was gonna go into the plain vanilla Linux desktop business. Then subsequently it said it wasn't. Now, on the threshold of its Sun Network confab tomorrow, it appears a Linux x86 desktop - reportedly dubbed the Java Desktop System - is back on the menu. However, it is widely believed the thing will be a typical Sun bait-and-switch for its latest darling, Solaris x86.

ISVs that got a copy of the desktop code last week to certify their own software on it say it's practically a model of Franciscan simplicity and consists of the SuSE 8.2 desktop operating system and a new cut of SunOffice, version 7.0, reportedly a very close relative of OpenOffice 1.3.1.

Other sources say it also includes Ximian's Gnome desktop and Ximian's Outlook-like Evolution.

In keeping with Sun's new upgrade policy, the software will be revved every quarter.

The Java Desktop System will be sold for a fee collected monthly or yearly - like one pays one's car insurance or school taxes - calculated on how many people work at the company buying the stuff. At least that's Sun's high-level view of the pricing scheme. Whether it works out that way in reality after negotiations is another. Sun insiders fancy the numbers Sun is going to put on the table are quite aggressive.

Orion, Sun's high-end integrated software stack, which also launches tomorrow and consists of all Sun's Sun ONE middleware, is supposed to be sold on the same basis. It will officially be called the Java Enterprise System, sources said. It is supposed to be available on Solaris, Linux and Solaris x86.

Some sources say that they have been given to understand that Sun will be selling the Java Desktop System, an alternative to Microsoft Office, unbundled for customers to run on their existing x86 machines - a strange departure for a hardware company.

Another rumor connected with Mad Hatter suggests that rather than go out and procure a conventional white box to run the Java Desktop System code on - as Sun suggested it would back in September - it'll sell the stuff on a single-board Grizzly, a version of its dual Xeon-based white box blade server passed off as a desktop.

Another set of rumors say Sun's going to "pull a Steve Jobs" and sashay it with a sexy widget run up by one of those fancy hardware designer outfits.

It's unclear how much credence to give either of these rumors, especially since the Sun Ray version of Mad Hatter involves hardware.