I just heard that Unisys is now insisting that implementors of GIF
get a license from them and pay them a royalty. Seems GIF uses LZW
compression, for which Unisys claims to have a patent.
My recollection is that there are rules about use of patented
technology in Internet standards -- something to do about the
patent owner has to make them available to all for a reasonable
fee. I don't know whether Unisys has done this or not.
There are some rules about this, but they don't apply since licenses for LZW
are in fact available and the terms are not obviously unreasonable. As a matter
of fact, you will find at least two Internet drafts that propose using patented
compression algorithms, draft-ietf-pppext-bsd-compress-02.txt and
draft-ietf-pppext-hpppc-00.txt, with the former actually using LZW!
As such, I don't think there's a valid objection to be made here on procedural
grounds. And I do agree that any such entanglements need to be described in the
RFC (although there's no requirement I'm aware of to do so).
This doesn't mean that you or anybody else can't object on principle. However,
this brings up a case I have never considered -- we have a stable, operational,
well documented format here that has caused no significant problems and in fact
has proven to be quite useful and violates no procedural rules I'm aware of.
What grounds can be used to argue for the removal of such a thing from a
specification? Frankly, I don't know any!
So I suggest that image/gif be removed from the Full Standard
version of MIME. The content-type registration will of course
remain in effect, but it probably needs to be amended to include
a warning to the effect that image/gif employs technology to
which someone claims a patent.
I think this is going to have to wait until things settle down. Here are
some of the issues involved:
(1) Several people have argued that the patent only applies to compression,
not decompression, and therefore has no impact on MIME viewers. However,
Unisys has apparently stated that they believe the patent applies to
decompression as well. If this is true and the patent is held to cover
decompression it would change the entire complexion of the situation.
(2) There are ongoing discussions about either replacing GIF with another
format or developing a new GIF-like format that avoids the patent issue.
(3) GIF isn't the only format that uses LZW -- both PostScript and TIFF
employ LZW compression. Now, the situation with these formats is different
in that use of LZW is by no means required. However, if decompression is
covered any PostScript Level II or TIFF viewer might fall under the
patent as well.
There are other open issues as well, of course, and as such I think any
change to the specification at this point would be premature.
Let's stamp out software patents in our lifetime.
Personally, I am in full agreement, but I have to separate my personal
position from my responsibilities here.