lzw code & patent
I'm cc'ing debian-legal for the legal part of this discussion.
LZW was a patented algorithm which was included in Unix's compress and
some versions of the gif file format.
There may not be reason to exclude lzw and related code as the LZW
patent is "running out".
I hope that this will be discussed further on debian-legal. I also am
curious as to whether Unisys can collect royalties after their patent runs
out. I suspect this may be illegal, or at least immoral. I also wonder
about whether patent laws can be used from one country on another.
Regardless, I don't think it's too important as long as we make sure
Debian doesn't do anything illegal.
The patent on lzw may have already expired. Due to it not expiring in all
countries at the same time, some caution is needed in deciding when to
include relevant lzw code. Perhaps in the style of non-us, or perhaps
When I figure out what kind of bugs to file against which packages I'll
look at doing a Mass Bug filing e-mail to Debian-devel. IMHO, it should
usually be a normal bug against packages that have purposely removed lzw
code, but I'll probably go with wishlist so as to ruffle fewer feathers.
Some might say that I should wait for the patent to expire in all
countries, but I don't know when that is, and even if I did, it wouldn't
hurt to have a place marker. This place marker might allow maintainers to
consider how lzw code could be brought back into their packages.
suggests that the Europe lzw patent is the last to expire which might
be June 19, 2004 or later in the thread, Japan's lzw patent on June 20,
2004. I'm not sure if these are enforcible, but it may be worth worrying
In http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=172181 written at Wed
Dec 18 03:15:08 2002, firstname.lastname@example.org says that it
"seems to be running out this month in the US. But is remains valid in .de
till 2004 (or 2003 if Unisys did not pay the last fee)"
Could anyone volunteer to find out which packages could benefit from, had
or have lzw code in them? Packages that depend on libungif type packages
could likely easily be changed to point to the equivalent libgif packages.
I did some preliminary research w/o looking at any code and found the
Some source packages with claiming to have lzw code:
giflib (giflib-bin, giflib3g, giflib3g-dev)
gimp-nonfree (gimp, libgimp-dev, libgimp1)
possibly contains lzw code:
Unlikely, but possibly contains lzw code:
non-free (lzw code could be there)
non-free (lzw code is claimed to be there)
Packages that disappeared that may have had lzw code:
xv (bug 98215)
Claimed not to contain lzw gif code:
openoffice.org (bug filed #172181)
gs (bug filed #177628)
gs-aladdin (bug filed #177631)
latex2html (description says: "Because of certain legal limitations on the
use of the GIF image format, GIF support is disabled in this package.",
but is lzw out of the original source?)
libtk-img (description says: "GIF (transparency supported, but not LZW)",
but is lzw not in the original source?)
hevea (description says: "This version of HeVeA is patched to generate by
default picture files in the PNG format instead of the GIF format.", but
is lzw out of the original source?)