The Mercurial license is GPLv2

[Matt Mackall]

On Mon, 2008-08-04 at 12:56 -0500, Dave Dribin wrote:
> On Aug 4, 2008, at 11:38 AM, Matt Mackall wrote:
> > Typically relicensing is done by finding all past contributors and
> > asking them if the new license is acceptable. And I already know one
> > person who would object before asking anyone. I for one am not a fan  
> > of
> > the BSD license. I would be very disappointed to see a company like
> > Apple come along, pick up Mercurial, make a bunch of shiny  
> > improvements,
> > then force me to pay for it if I wanted a copy.
> 
> At the same time, GPL blocks out some legitimate usages for Mercurial  
> that would actually be beneficial to Mercurial.  Mercurial won't see  
> any commercial GUI front-ends or adoption into closed-source IDEs, for  
> example.

There's absolutely nothing that prevents commercial GUIs, of course: you
just have to offer to distribute the source. You can even make a
proprietary GUI, it will just be a bit slower than a GPLed one. And
that's fine, because I'm much more interested in supporting the latter.

As it happens, there are already at least a couple Eclipse IDE plug-ins
despite Eclipse being non-GPL compatible, so the barrier must not be
very high.

>   One benefit of Subversion over any of the leading DVCs is  
> its more liberal license [1].  This has resulted in a much wider  
> adoption of Subversion than Mercurial can ever achieve.  On the  
> pragmatic/practical side, Apple has very little incentive to modify  
> Mercurial as they'd want it to be compatible with the "official" open  
> source version.

The Apple reference is in regards to their embrace of FreeBSD, which has
taken that operating system from obscure to popular and proprietary. If
that's the FreeBSD folks' idea of success, then great for them; in my
view, it's a rather dismal failure. 

And it's not hard to imagine someone wanting to make an extended
proprietary version of Mercurial as I've already been approached about
it. 

> Perhaps a middle ground where the Mercurial back-end library is LGPL  
> would satisfy both camps.

It's not gonna happen, folks.

-- 
Mathematics is the supreme nostalgia of our time.