[cairo] Pango License

Behdad Esfahbod behdad at behdad.org
Wed Dec 15 13:30:29 PST 2010

On 12/15/10 15:36, Thomas Stover wrote:
>> From: Travis Griggs <travisgriggs at gmail.com>
>> Is there any hope of Pango every becoming dual licensed?
>> I just found out today, that because Pango is exclusively LGPL, we're  
>> dead in the water using it for some of our customers. At least on  
>> platforms such as OSX and Windows. 
> wow, I'll bite. What reason do the suits have for saying yes to LGPL on
> say Linux, but no on "platforms such as OSX and Windows"?

On Linux, they don't have to ship the LGPL code, they just use it.

There are considerable problems with shipping LGPL code.  They are evident and
clear if you read the text of the LGPL.  For example, if you want to ship one
binary (embedded firmware, executable, installer, etc), then by item number 6
of the LGPL you have to allow reverse-engineering of your product:

  6. As an exception to the Sections above, you may also compile or
link a "work that uses the Library" with the Library to produce a
work containing portions of the Library, and distribute that work
under terms of your choice, provided that the terms permit
modification of the work for the customer's own use and reverse
engineering for debugging such modifications.

It may sound far-fetched, but one can argue that you can read the above
paragraph as in to allow hacking the executable to circumvent any customer
license checking code for example.

The rest of item number 6 also require the distributor to make all the source
to their executable available in object files such that users can relink it
with an updated LGPL library if the desire to.  You cannot find one company
that would be happy to do this.  If nothing else, it's a lot of work to do.

That said, doesn't mean that all companies follow that section correctly.  For
example, the latest versions of Sony TVs and some other consumer devices
(Bluray players, etc) use Pango and cairo to provide i18n text.  They make the
sources to pango and cairo available on their website, but no way for me to
build a new firmware using an updated pango.  Reminds me that I wanted to
contact the SFLC about this.


> Or did I
> misunderstand? Don't mean to divert into a tangent, but after researching
> to heck out licenses, I was going with LGPL for some things I'm releasing,
> and therefor particularly interested in what sort of non-logic is going
> around in who knows what legal magazine this week.

More information about the cairo mailing list