ARJ Software dead?

[nikkho]

Hope it is only me, but a week ago, I tried to access ARJ Software just as a curiosity to see if any news, and found it down. I tried just now again, and still down.
Hope this legendary project is not dead... I know its improvements since latest 10 years have been minor, but it is a sad news for us, lovers of compression.
Would be great seen it as an official open source (as oposite to the unknown origin of http://arj.sourceforge.net).

http://www.arjsoftware.com

[Stephan Busch]

In my opinion this archiver is dead. With many archivers just supporting decompression and commercial license for the encoder,
no one would create .ARJ archives anymore. There are enough free alternatives around and unless commercial software has
something special to offer, no one would use it.

Over the years I tried several times to contact them asking for a Hall of Fame picture of Robert Jung, the format inventor,
but they never responded.

[Matt Mahoney]

I didn't know that anyone still uses ARJ. Anyway, I tested the open source version on LTCB and it works nicely, but it is about twice as slow as zip with slightly worse compression. http://mattmahoney.net/dc/text.html#3286

ARJ was patented in the U.S. in 1991, so that patent presumably expired in 2011. From the claims it looks like the patent covered using hash tables with FIFO queues to find LZ77 matches.

[nburns]

I didn't know that anyone still uses ARJ. Anyway, I tested the open source version on LTCB and it works nicely, but it is about twice as slow as zip with slightly worse compression. http://mattmahoney.net/dc/text.html#3286

That sounds sort of like a beverage that costs twice as much as tap water, but is slightly less effective at quenching thirst. I'm sure it was more impressive in 1991.

[Matt Mahoney]

Probably why it lost to PKZip. Today, the patent would have killed it.

[nburns]

Probably why it lost to PKZip. Today, the patent would have killed it.

I thought I kind of understood the history of the .zip format, but I took another look at wikipedia just now and discovered yet another wrinkle that I didn't know about. I always assumed that PKZip popularized its own compression format, but recently when I read some history on zlib, I came to the conclusion that I had been mistaken, because zlib was designed around a brand new algorithm, which was identical to PKZip's deflate -- so deflate must have come from zlib. Actually, the history seems to be more complicated than that. Apparently, Phil Katz invented the algorithm and format which was used first in PKZip. Then Jean-Loup Gailly and Mark Adler invented a brand new algorithm, patent-free, that generated the exact same *format* as deflate -- zlib.

I was only 11 in 1991, but I have remarkably clear memories of the computers I used and what I did with them, and the memories are tinged with nostalgia. I was talking to a coworker about old computer stuff recently, and I suddenly became aware that I probably have clearer memories of the computers than anything else from that far back -- even people. It was a unique time though, and computers have steadily gained in importance since then, which is more than can be said of any of the people I knew. I'm hoping that someday these memories will be fascinating to people and will be the subject of documentaries with high production values, so I feel like I didn't waste my youth.

[caveman]

I thought I kind of understood the history of the .zip format, but I took another look at wikipedia just now and discovered yet another wrinkle that I didn't know about. I always assumed that PKZip popularized its own compression format, but recently when I read some history on zlib, I came to the conclusion that I had been mistaken, because zlib was designed around a brand new algorithm, which was identical to PKZip's deflate -- so deflate must have come from zlib. Actually, the history seems to be more complicated than that. Apparently, Phil Katz invented the algorithm and format which was used first in PKZip. Then Jean-Loup Gailly and Mark Adler invented a brand new algorithm, patent-free, that generated the exact same *format* as deflate -- zlib.

The strangest thing here is that the FAQ from gzip (gzip was written before zlib) points to a 0.9 version of zip for prior art, the link goes to the info-zip site, but its own history states this:
August 1992 - Info-ZIP releases UnZip 5.0 and Zip 1.9, both fully supporting the new deflate compression method introduced in PKWARE's PKZIP 1.93a beta release.
Were early versions of gzip based on a different compression method, not Deflate, coming from a zip 0.9 product?

Ok I've found more informations here.

IMPORTANT NOTES:

- pkzip 1.93a is only an alpha version (see historical notes below). If
you wish to create zip files compatible with the official version of
pkzip (1.10), you must use zip 1.0. zip 1.9 cannot create files
with the old compression method (implosion).

- zip 1.9 is is compatible with pkzip 1.93a, except when two features
are used: encryption or zip file created in a pipe or on a non
seekable device. pkzip versions of 2.0 will support such files, and
unzip 5.0 already supports them. (Thanks to Phil Katz for accepting
our suggested minor changes to the zip file format.)

[...]

Historical notes:

At the time of release of zip 1.9, the official released version of
PKZIP is version 1.10. PKZIP 1.93a is only an alpha version, which was
released in October 1991. It was supposed to be replaced soon after
with an official release of pkzip 2.0. However, Phil Katz has not yet
announced a release date at the time of writing (Aug 19th, 1992).

Beta versions of zip compatible with pkzip 1.93a have been available
since February 1992 to the info-zip group (see the file 'history').
The zip authors would have preferred to release zip 2.0 only after
pkzip 2.0(*), to ensure full compatibility in case of archive format
changes between pkzip 1.93a and 2.0. However we feel that we cannot
delay any further the release of zip 1.9, since all the major features
that we wanted to put in are now available and well tested by the
info-zip group.

(*) The version number for the new pkzip was planned to be 2.00, but may
be increased to a number greater than 2.2 to prevent confusion with
several bogus versions, which may destroy all the data on your hard
disk if you run them.

[Matt Mahoney]

Interesting history of the development of PKZIP. http://www.bbsdocumentary.com/librar.../LAWSUITS/SEA/

Originally Phil Katz wrote PKARC, a faster ARC-compatible archiver. SEA (developers of ARC) sued and won, but the community was so outraged that they stopped using ARC. Later Katz developed a new format PKZIP, which eventually became the dominant archive format.

Unfortunately Katz was not so successful. He died alone in 2000 at age 37 from alcohol poisoning, abandoned by his family and hiding from the police. There is a fascinating account of his tortured life in http://www.bbsdocumentary.com/librar...EA/katzbio.txt

[nburns]

That's a tragic story. It's not quite true that his family abandoned him. It was his dad's untimely death that pushed him toward the edge. It doesn't sound like he ever got along all that well with his mother. It shows the emptiness that can follow success, which is probably always surprising and unexpected.

[caveman]

Did you know that Terry Welch (the W in LZW) died in 1985? Wikipedia states that he filed the patent application for LZW which led to funny things like the "Burn all GIFs" campain a few years later...
http://en.wikipedia.org/wiki/Graphic...nt_enforcement

[nburns]

Did you know that Terry Welch (the W in LZW) died in 1985? Wikipedia states that he filed the patent application for LZW which led to funny things like the "Burn all GIFs" campain a few years later...
http://en.wikipedia.org/wiki/Graphic...nt_enforcement

His wikipedia page doesn't have a date of death, so I think he's still alive, or wikipedia thinks he is: http://en.wikipedia.org/wiki/Terry_Welch

[caveman]

His wikipedia page doesn't have a date of death, so I think he's still alive, or wikipedia thinks he is: http://en.wikipedia.org/wiki/Terry_Welch

Check here:
http://www.davidsalomon.name/DCBiog/BiogDComp.pdf