Fight! Sun and IBM have been joining verbal battle over the future of the server OS and Java in recent weeks.

In the most recent skirmish, Sun's software EVP Jonathan Schwartz wrote an open letter to IBM's Sam Palmisano on IBM's options for the desktop after Big Blue had issued a memo to all staff urging them to switch over to Linux on their desktops.

Schwartz's response was fourfold:

  1. Sun's already moved to a non-Microsoft desktop - specifically, Java
  2. Guess what? Java saves you money
  3. Try our Java Enterprise server instead of your clunky old Lotus Notes/Websphere thing
  4. What happened to Linux - why aren't you reselling it?

He concluded: "I guess I just don't understand your Linux strategy."

On Wednesday, IBM's VP of emerging technology Rod Smith, is reported to have repeated IBM's apparently sincere offer to help Sun turn Java into an open source product, providing technical resources and source code while Sun provides documentation and test facilities.

This is not the first time IBM has challenged Sun in this way: the previous such challenge emerged from IBM after Sun's flamboyant CEO Scott McNealy said his company would benefit from open source software.

Naturally enough, the open source community's response has been overwhelmingly negative about Sun's insistence on charging money for a product it developed and which it sees as its crown jewels. Accusations being flung around include support by Sun for SCO and its recent copyright lawsuits over Linux code.

A more measured response comes from Web architect Ganesh Prasad who suggests that Sun has much to gain by moving to open source. Prasad argues that Sun is likely to lose against Microsoft's .NET in the enterprise because of the ubiquity of .NET-friendly features in Internet Explorer. Consequently, a radical solution involving open source is the only response, along with making J2EE cheaper.

Clearly, Sun has much to gain from moving to open source but much to lose too, since Sun shareholders, McNealy among them, won't be ecstatic about giving away a cash cow. However, Prasad bolsters his argument by saying that Microsoft is vulnerable because it's in financial trouble, citing the loss of large contracts such as Newham Council. In fact, Newham's contract saved £1 million - a fair amount for the burghers of Newham but a drop in the ocean for Redmond.

What's clear is that Microsoft will be happy to see its chief rivals squabbling among themselves, secure in the knowledge that a unified strategy versus a multitude of voices invariably wins on a physical battlefield - and could well do so on this occasion. In the short to mid-term at least.