Both RMS and I have been critical of Mono, which is an implementation of Microsoft's C# language infrastructure for GNU/Linux systems. (Until recently, at Novell, Miguel De Icaza has led a team of developers working on Mono.)
Most have probably heard that the Attachmate acquisition of Novell completed last week, and that reports of who will be fired because of the acquisition have begun to trickle. This evening, it's been reported that the developers working on Mono will be among those losing their jobs.
In the last few hours, I've seen some folks indicating that this is a good outcome. I worry that this sort of response is somehow inspired by the criticisms and concerns about Mono that software freedom advocates like myself raised. I thus seek to clarify the concerns regarding Mono, and point out why it's unfortunate that these developers won't work on Mono anymore.
First of all, note that the concerns about Mono are that many Microsoft software patents likely read on any C# implementation, and Microsoft's so-called “patent promise” is not adequate to defend the software freedom community. Anyone who uses Mono faces software patent danger from Microsoft. This is precisely why using Mono to write new applications, targeted for GNU/Linux and other software freedom systems, should be avoided.
Nevertheless, Mono should exist, for at least one important reason: some developers write lots and lots of new code on Microsoft systems in C#. If those developers decide they want to abandon Microsoft platforms tomorrow and switch to GNU/Linux, we don't want them to change their minds and decide to stay with Microsoft merely because GNU/Linux lacks a C# implementation. Obviously, I'd support convincing those developers to learn another language system so they won't write more code in C#, but initially, the lack of Free Software C# implementation might impede their switch to Free Software.
This is a really subtle point that has been lost in the anti-Mono rhetoric. I am not aware of any software freedom advocate who wants Mono to cease to exist. The problem that I and others point out is this: it's dangerous to write new code that relies on technology that's likely patented by Microsoft — a company that's known to shake down or even sue Free-Software-using companies over patents. But the value of Mono (while much more limited than its strongest proponents claim) is still apparent and real: it has a good chance to entice developers living in a purely Microsoft environment to switch to a software freedom environment. It was therefore valuable that Novell was funding developers to work on Mono; it's a bad outcome for software freedom that those developers will lose their jobs. Finally, while perhaps some of those developers might get jobs working on more urgent Free Software tasks, many will likely end up in jobs doing proprietary software development. And developers switching from Free Software work to proprietary software work is surely always a loss for software freedom.
Update (2011-05-04): ciarang pointed out to me that Mono for Android is proprietary software. As such, it's certainly better if no one is working on that proprietary project anymore. However, I would make an educated guess that most of the employed Mono developers at Novell were working on the Free Software components, so the above analysis in the main blog post still likely applies in most cases.
