ACE is a proprietary format, but they do offer a free DLL
for Win32 @ http://www.winace.com/licence.html. So you could
at least extract, but not compress them.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
From the FAQ:
"Supporting for ACE archives can be implemented, if source
code of that format will be available, and if license of source
code will allow using that code. Unace.dll from authors of
ACE program is not compatible with plugin interfaces of 7-Zip
(Unace.dll works with files, but 7-Zip allows plugins to work
only with abstract streams). So 7-Zip can't use Unace.dll
without complex wrapper."
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
-
2008-03-10
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> From the FAQ:
>
> ... "So 7-Zip can't use Unace.dll without complex wrapper."
So, has anyone ever written such a complex wrapper for it?
> shockzor @ 2005-05-01 11:38
>
> Would be little benefit to support this format since only few people use it.
Same could be said of bz2 on Windows, for which 7-zip is made. Also, never used or even seen arj, cpio, split, swm, tpz or wim files, and I've seen and used a LOT of compressed archives! So by your argument, none of these should be supported either. ;-) VERY poor argument, weak argument does not hold up to logical scrutiny.
> Would be really disappointed if I saw 7-Zip had support for ACE.
>
> Supporting a non-free format like ACE would be a good reason _not_ to use 7-Zip.
That's a personal problem. There's no need to be a format Nazi. Read/extract support of ACE would be great, because then it is possible to extract and create a 7-Zip archive and eliminate the ACE archives if you so desire. Again, a weak argument for non-support.
Have you ever supported 7-zip project in any tangible way, with donations, code development or document submissions, or user support? If yes, then great. If not, you have no cause to complain about support.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
-
2008-03-10
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Originator: NO
I've read the license for the UNACE Decompression Library v2.6. The license forbids copying any portion of the license. Although I think FAIR USE would allow for paragraphs to be copied for general discussion, I am unclear, so I won't even quote the license. It doesn't bode well for support.
Reading on, it does not explicitly say, but it does seem to strongly imply that there are two conditions for using the UNACE.DLL in other software. Therefore, my statements below are to be considered as paraphrases, my personal interpretation, and may or may not reflect the original intent of the corporation that creates the WinACE product.
1) The software that uses UNACE.DLL must promote the ACE file format with the implied intent to expand the user base.
2) In support of 1) above, the software must also allow the user to select the UNACE.DLL for any of the file formats that UNACE.DLL supports, with the implied intent to further expose users to the capabilities of the ACE software to handle not only ACE but other file formats as well.
Now, I think I have already established that the predominant intent in the 7-zip community is to extract ACE files for the purpose of conversion to other formats that 7-zip can support.
Therefore I find it reasonably safe to assume that any software which in any way interfaces with the DLL (either by direct calls from a GPL or LGPL source, or by means of some wrapper code), would be construed by the corporation as a violation of both their implied license conditions and not favorably received.
It seems as though it is not a question of technical ability to create support for ACE extraction in 7-zip (however convoluted it may be to do so), but rather a radically different philosophy of not only software development, but file format licensure. It is my opinion that the end result, whether intended or not, but seemingly the aim of the corporation, is to hold YOUR DATA hostage in ITS proprietary file format. If this is not the case, the corporation must radically modify the license for UNACE.DLL.
An aside, it seems highly questionable whether or not OTHER very popular programs that provide access to the UNACE.DLL, such as WinRAR, are even in compliance with the license. Although WinRAR allows you to extract ACE files using UNACE.DLL, it does NOT allow the user to select the UNACE.DLL to handle extraction of other formats, such as RAR, which would seem to violate the implied terms of the license.
In any case, the vagueness of the license itself is a major deterrent. :-(
For the record, I have a valid WinACE license, and have also donated to 7-zip. I bought the WinACE license long before I became aware of 7-zip, and perhaps before 7-zip existed. The ACE file format and the software and performance was great at the time. But they stopped releasing for many years, stopped fixing bugs, seemingly stopped all development. Other file formats and software have continued to innovate and provide faster performance, higher compression rates, more advanced features, and so I have for many years considered ACE to be obsolete. Not because of a prejudice against "an evil empire" :-) but merely because of their lack of development of their own product!
Because of the bad experience -- paid for a license, then stop development, never fix major security bugs such as the "..\" bug that allows arbitrary execution of code, handy for a hacker to create a decoy self-extracting archive with UNACE.DLL embedded to instantly allow total control of your computer, and the inability to get UNACE.DLL support for any GPL/LGPL software -- I'm tired of ACE and if I never see it again, I'll be happy.
If the company decides that their file format is a more important innovation to the world than the small amount of profits from the restrictive license model, then maybe they can embrace open source, redefine the license for UNACE.DLL (perhaps ACE.DLL too for compression) and so meet both of the objectives described in the license: support ACE file format and expose more people to the great ACE file format. ;-)
7-Zip author Igor Pavlov deserves great credit for choosing this model, and it is because of this choice that I not only became AWARE of the 7-Zip application (back when I searched for PPMd compression support I found 7-zip after some years), but also the many features of the file format. It's a very clear choice: if you want to maximize exposure of a format to users, open-source it, allow open development, and keep releasing new versions each few months, with bug fixes. ;-)
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Logged In: YES
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ACE is a proprietary format, but they do offer a free DLL
for Win32 @ http://www.winace.com/licence.html. So you could
at least extract, but not compress them.
Logged In: YES
user_id=232094
Would be little benefit to support this format since only few
people use it.
Would be really disappointed if I saw 7-Zip had support for
ACE.
Supporting a non-free format like ACE would be a good
reason _not_ to use 7-Zip.
Logged In: YES
user_id=232094
See the FAQ: http://www.7-zip.org/faq.html
From the FAQ:
"Supporting for ACE archives can be implemented, if source
code of that format will be available, and if license of source
code will allow using that code. Unace.dll from authors of
ACE program is not compatible with plugin interfaces of 7-Zip
(Unace.dll works with files, but 7-Zip allows plugins to work
only with abstract streams). So 7-Zip can't use Unace.dll
without complex wrapper."
Logged In: YES
user_id=706287
Originator: NO
> From the FAQ:
>
> ... "So 7-Zip can't use Unace.dll without complex wrapper."
So, has anyone ever written such a complex wrapper for it?
> shockzor @ 2005-05-01 11:38
>
> Would be little benefit to support this format since only few people use it.
Same could be said of bz2 on Windows, for which 7-zip is made. Also, never used or even seen arj, cpio, split, swm, tpz or wim files, and I've seen and used a LOT of compressed archives! So by your argument, none of these should be supported either. ;-) VERY poor argument, weak argument does not hold up to logical scrutiny.
> Would be really disappointed if I saw 7-Zip had support for ACE.
>
> Supporting a non-free format like ACE would be a good reason _not_ to use 7-Zip.
That's a personal problem. There's no need to be a format Nazi. Read/extract support of ACE would be great, because then it is possible to extract and create a 7-Zip archive and eliminate the ACE archives if you so desire. Again, a weak argument for non-support.
Have you ever supported 7-zip project in any tangible way, with donations, code development or document submissions, or user support? If yes, then great. If not, you have no cause to complain about support.
Logged In: YES
user_id=706287
Originator: NO
I've read the license for the UNACE Decompression Library v2.6. The license forbids copying any portion of the license. Although I think FAIR USE would allow for paragraphs to be copied for general discussion, I am unclear, so I won't even quote the license. It doesn't bode well for support.
Reading on, it does not explicitly say, but it does seem to strongly imply that there are two conditions for using the UNACE.DLL in other software. Therefore, my statements below are to be considered as paraphrases, my personal interpretation, and may or may not reflect the original intent of the corporation that creates the WinACE product.
1) The software that uses UNACE.DLL must promote the ACE file format with the implied intent to expand the user base.
2) In support of 1) above, the software must also allow the user to select the UNACE.DLL for any of the file formats that UNACE.DLL supports, with the implied intent to further expose users to the capabilities of the ACE software to handle not only ACE but other file formats as well.
Now, I think I have already established that the predominant intent in the 7-zip community is to extract ACE files for the purpose of conversion to other formats that 7-zip can support.
Therefore I find it reasonably safe to assume that any software which in any way interfaces with the DLL (either by direct calls from a GPL or LGPL source, or by means of some wrapper code), would be construed by the corporation as a violation of both their implied license conditions and not favorably received.
It seems as though it is not a question of technical ability to create support for ACE extraction in 7-zip (however convoluted it may be to do so), but rather a radically different philosophy of not only software development, but file format licensure. It is my opinion that the end result, whether intended or not, but seemingly the aim of the corporation, is to hold YOUR DATA hostage in ITS proprietary file format. If this is not the case, the corporation must radically modify the license for UNACE.DLL.
An aside, it seems highly questionable whether or not OTHER very popular programs that provide access to the UNACE.DLL, such as WinRAR, are even in compliance with the license. Although WinRAR allows you to extract ACE files using UNACE.DLL, it does NOT allow the user to select the UNACE.DLL to handle extraction of other formats, such as RAR, which would seem to violate the implied terms of the license.
In any case, the vagueness of the license itself is a major deterrent. :-(
For the record, I have a valid WinACE license, and have also donated to 7-zip. I bought the WinACE license long before I became aware of 7-zip, and perhaps before 7-zip existed. The ACE file format and the software and performance was great at the time. But they stopped releasing for many years, stopped fixing bugs, seemingly stopped all development. Other file formats and software have continued to innovate and provide faster performance, higher compression rates, more advanced features, and so I have for many years considered ACE to be obsolete. Not because of a prejudice against "an evil empire" :-) but merely because of their lack of development of their own product!
Because of the bad experience -- paid for a license, then stop development, never fix major security bugs such as the "..\" bug that allows arbitrary execution of code, handy for a hacker to create a decoy self-extracting archive with UNACE.DLL embedded to instantly allow total control of your computer, and the inability to get UNACE.DLL support for any GPL/LGPL software -- I'm tired of ACE and if I never see it again, I'll be happy.
If the company decides that their file format is a more important innovation to the world than the small amount of profits from the restrictive license model, then maybe they can embrace open source, redefine the license for UNACE.DLL (perhaps ACE.DLL too for compression) and so meet both of the objectives described in the license: support ACE file format and expose more people to the great ACE file format. ;-)
7-Zip author Igor Pavlov deserves great credit for choosing this model, and it is because of this choice that I not only became AWARE of the 7-Zip application (back when I searched for PPMd compression support I found 7-zip after some years), but also the many features of the file format. It's a very clear choice: if you want to maximize exposure of a format to users, open-source it, allow open development, and keep releasing new versions each few months, with bug fixes. ;-)