First, I really don't think users care a whole lot about consistency. Look at Linux applications; you have loads of different looks and feels all over the place, with no consistency at all. What I care about, as someone who uses Linux, OS X, Windows, and others, is that the same applications be available everywhere, and work the same way on every platform.

But I think there are some bigger cultural points. Did anyone in the Java community cry "foul" when Perl developers decided to clone the Lucene search engine? Did anyone cry foul when Ant and JUnit were re-implemented in any number of different languages?

Sun is rightly criticized for wanting the appearance of open source, but not the substance. But the same thing is going on here. If the developers of Evolution didn't want other people to see the source code, they shouldn't have released it. If they didn't want other people to reimplement it, they should have patented the ideas and copyrighted the user interface. Of course, that's anathema to the open source community, and rightly so. But if you're going to be in the open source community, you've got to live with the consequences.

There's certainly an element in the Linux community that likes to consider itself "open source", but only if the right people are playing in the sandbox. Unfortunately, that's a recipe for failure. And if Linux is going to succeed as a desktop OS, it's got to get beyond that.

Mike Loukides
Editor, O'Reilly