But you could also make the arguments against Samba and the OpenChange MAPI connector, or even MS Office support in OpenOffice.

Sure, absolutely. And they’d be legit arguments. The difference isn’t qualitative, but quantitative, so it’s entirely possible that the current Mono-bashing is more paranoid than sensible.

Obviously I can’t speak for Stallman or anybody else, but the main thing that makes me jittery about Mono is the size of the attack surface. Specifically, the volume of code that deliberately duplicates MS libraries and architecture.

I don’t worry as much about Samba or MAPI or Exchange or AD connectors or protocol-oriented reimplementations of MS code generally, precisely because they’re data-driven. Samba’s purpose is to deal with wire data that’s in a MS-controlled format. They only have to replicate the behavior of MS code long enough to get the data off the wire. Likewise OOO, except that it’s non-wire data.

That’s risky, but (to me at least, IANAL) it seems substantially less risky than Mono. Mono has as its purpose the reimplementation of MS libraries and MS code behavior. That’s makes it useful and convenient, but increases the risk of collision with patents.

Just $.02. I wouldn’t want to discourage anyone from supporting Mono, and I think the hubbub has as much or more to do with the distributions issues as any vulnerability of Mono itself.

Stallman’s description is just unclear is all. No, the problem is not C# the language. The problem is that the Mono apps that you’re a huge fan of are vulnerable to lawsuits. They’re free-as-in-beer, but there’s no way to be sure that they’re free-as-in-speech. Because of their architecture and dependencies, Microsoft has the option of deciding, at some later date, to argue in court that Mono, or those apps, or whatever, are *not* free-as-in-speech after all. Despite the free-as-in-speech Mono license that supposedly protects them. In fact there may be deliberately concealed vulnerabilities. It wouldn’t be the first time.

Stallman’s point is that MS knows a lot more about the legal vulnerability of Mono than you do, which makes it much easier for them to try to alter the legal status of those apps at some point in the future. And the inclusion of those apps in distros allows MS to attack the distributors.

Which means that somebody — probably lots of somebodies — then have to go to court and defend the free-as-in-speech-ness of the apps. How much effort are you willing to put into that defense in exchange for easy access to Mono apps today? Because at that point it would be a much bigger question than whether or not you have to start paying MS or give up the use of the apps. A lawsuit like that could easily eat up all the resources the EFF could throw at it.

If MS does decide to go after Canonical (or whomever) the purpose of the suit won’t be to get you (Ryan) to stop using Tomboy (or to start paying for it). The purpose will be to either take out or take over Ubuntu and any other distros or institutions that are vulnerable.

Furthermore, what if Mono didn’t offer C# as a language choice? Does Mono now become ok?

As you say, C# is submitted as an ECMA standard. There are a number of namespaces not included in that group, but since Microsoft have already reached an agreement not to pursue patent infringement with Novell directly, I don’t see how their implementation within Mono can be questioned.

I’m all for choice as a developer and an end-user, and for me – Mono provides just that.

There are some good comments @ http://andreasdevblog.wordpress.com/2009/06/29/c-and-the-rights-to-use-it/ related to the same subject, mostly clearing up the original author misreading of RMS’s warning.

The fact that ECMA, a standards making body agrees that C# is a standard does not give you a license to patents needed to implement the standard. A court will have no problem with a standard that requires you to pay if you implement it, because being “standard” has no legal importance.