“What's in a name?” some bloke in the sixteenth century once asked. As Microsoft knows, quite a lot. What you call something can have a major influence on how you think about it. So how Microsoft talks about free software is important – not least for the clues that it gives about its latest tactical move to defang the open source threat.

This is by no means a new approach. Some years back I was in a meeting with a senior Microsoftie in the UK. Nominally, he wanted to talk to me about Microsoft's “new” free software-friendly attitude – isn't it telling how often Microsoft keeps promising that *this* time it really means it? But judging by the frantic scribbles of the marketing droid at the back of the room, who was trying to capture everything I said (don't they have tape recorders at Microsoft?), they were more interested in pumping me for insights into free software that might furnish some conceptual ammunition against it.

What was noteworthy was that at this period Microsoft couldn't even bring itself to utter the words “free software” or “open source”. Instead, throughout the hour-long chat I had with him, the Microsoftie insisted on referring to something he called “non-commercial software”. The intent was plain: only Microsoft and its proprietary chums sold “commercial” software, while the other, unnameable stuff – aka free software – wasn't “real” or “commercial” stuff, but some kind of toy version that no sane IT manager would touch.

Well, that didn't work as a tactic, but it hasn't stopped Microsoft from returning to it recently:

"Today, but increasingly in the future, we are all going to be 'mixed source'," Microsoft's top intellectual property lawyer said in a lunchtime interview on Thursday. To bolster his claim, Horacio Gutierrez notes Microsoft is releasing plenty of stuff as open source, while open-source companies like Red Hat often license commercial software alongside their open-source products. "I actually think the war between proprietary and open source is a thing of the past," he said.

So there we have it: “open source” is no longer a useful term, everything is “mixed source”. Microsoft has obviously woken up to the fact that the “free” and “open” memes are increasingly powerful, as people realise the advantages of sharing and collaborative development. Microsoft has been trying to co-opt that feel-good factor for a while, first with its “Shared Source” label – free software without the freedom – and more recently by getting a couple of its licences approved by the Open Source Initiative.

Having made this partial rapprochement – so that Gutierrez can claim with a certain plausibility that Microsoft too is releasing loads of open source stuff – the company is now trying to effect a sleight of hand: since Microsoft is releasing open source, and open source companies often have proprietary offerings, ergo there is now no difference between the two, and we should just call it all “mixed source”.

Nice try, Horacio.

The central fallacy in this argument is that open source companies are somehow equivalent to open source. While the best of them do indeed contribute back to the projects they are based on, they are, nonetheless, essentially parasitic – in the nicest possible way, of course. They necessarily feed off the work of the many contributors to free software, even when they employ all the main coders in-house. Because without the community, there is no free software. Without the feedback from users, and the bug reports and patches, so-called open source companies are little more than proprietary software houses that give away trial versions for free.

However much these open source companies may support free software they are and always will be incidental to it. The fact that some sell proprietary versions of open code does not prove that there is no essential difference between closed and open software, simply that such companies either do not understand or value its essence. Indeed, Gutierrez's invocation of them shows that they represent a subtle danger to real free software: not so much for what they are doing or might do, as for the succour it gives to Microsoft's attempts to play down the core strength of open source – putting users in the driving seat – compared to its own model of unbending, centralised control.

Microsoft's Mafia-like obsession with enforcing “control” and demanding “respect” is reflected in a later statement from Gutierrez in the same interview – well, more of a threat, actually:

"If every effort to license proves not to be fruitful, ultimately we have a responsibility to customers that have licenses and to our shareholders to ensure our intellectual property is respected," he said.

Software patents - what he is referring to here - are intellectual monopolies specifically framed to stop the kind of frictionless sharing of programming ideas that lies at the heart of free software, and that powers its unique ability to build on the work of others. In many ways, such monopolies go to the heart of the difference between the worlds of open and closed software: any company unwilling to licence freely software patents it may have acquired (for defensive reasons, say, against patent trolls – the ultimate symptom of a diseased system) is by definition not a company that truly supports free software. There is no “middle” ground – sorry, Horacio.

Glyn Moody writes about openness at opendotdotdot.