Last week’s announcement saw Microsoft announce that it will work with Novell on Windows/Linux interoperability, issue SUSE Linux Enterprise Server support vouchers to joint customers, recommend SUSE to those that want it, and promise not to sue SUSE Linux users or developers for patent infringement.

The news is not so good for the open source community at large, however, as Microsoft made it clear that only SUSE users and developers, as well as unsalaried Linux developers, are protected.

Let me be clear about one thing, we don’t license our intellectual property to Linux because of the way Linux licensing GPL framework works, that’s not really a possibility, said Microsoft chief executive, Steve Ballmer.

Novell is actually just a proxy for its customers, and it’s only for its customers, he added. This does not apply to any forms of Linux other than Novell’s SUSE Linux. And if people want to have peace and interoperability, they’ll look at Novell’s SUSE Linux. If they make other choices, they have all of the compliance and intellectual property issues that are associated with that.

The deal is another blow for Linux leader Red Hat Inc, which is clearly still in Microsoft’s intellectual property sights, as well as those of Oracle Corp following the recent announcement that the database giant will undercut it on support pricing.

Not surprisingly, Red Hat dismissed the patent licensing agreement. An innovation tax is unthinkable. Free and open source software provide the necessary environment for true innovation. Innovation without fear or threat. Activities that isolate communities or limit upstream adoption will inevitably stifle innovation, it said in a statement.

As well as Red Hat, the likes of IBM, HP, Google, Oracle and many others remain under the threat of Linux-related IP claims from Microsoft, as do individual developers who get paid for their Linux code work.

While Microsoft announced that it would not assert its patents against individual open source developers, the company’s general counsel, Brad Smith qualified that offer. These are individuals who are creating code, contributing code, they’re not being paid for that code. They’re not creating it as part of their job, he said.

While the romantic image is of Linux being created by many individual developers working for the common good, the vast majority of Linux development is done by developers paid or sponsored by Linux-friendly vendors.

Microsoft’s patent commitment does not apply to the majority of Linux developers, unless they transfer their commitment to Microsoft’s Linux project of choice, it seems. The second thing we did in this area was add a promise that goes to developers, even developers who are getting paid to create code to opensuse.org, code that Novell then takes and incorporates into its distribution, added Smith.

The plan could therefore create a two-tier Linux business, with one tier that is approved and protected by Microsoft, and one that faces potential litigation, although the Free Software Foundation’s general counsel, Eben Moglen, has reportedly stated that it could therefore be a violation of the GNU General Public License.

While admitting that he was yet to see the terms of the agreement, Moglen postulated that it could fall foul of section seven of the GPL, which requires distributors to pass on the right to distribute software without additional permission.