Hi there!

Maybe some of you remember 7-zip from Better Zip Compression thread. It's opensource freeware and offers optimized=best available compression in .zip format and equal or better compression than RAR3 in it's own format .7z. What distracts ppl in my experience is the unusual GUI and the looong line of parameters you can set (reminds me of the days before the alt-presets ).

Lately I found ZipZag, another shareware archiver. There are two things why I post this here: Firstly, it's the only one I know that handles 7-zip with a mainstream-archiver-like GUI, but what really impressed me is how many languages/dialects are supported. I think some of you pplz especially like this one:



@Mods: Please don't delete this image - it's only 17K (less than many avatars including mine).

Cheers tigre

Image don`t work. 7-zip already supports many languages.

Thanks, Cobra. Now it should work. I thought language -> English dialect -> Hacker would be something especially for you.

You may use this full featured software for evaluation purposes only, for a period of maximum 30 days. If you decide to keep the software after the 30 days period, you must purchase a licensed copy for just 25$ (15.5£/ 23.4€/ 42.3AUD/ 38.4CAD)

7-Zip program is distributed under the GNU LGPL, downloadable with no cost, uncrippled and truly free.

... and it offers compression ratios better than RAR3 - it's just great! This is enough for you? Fine - for me too. We don't need ZipZag.

But why not give people who want an easy to use GUI what they want? This will make more people use the format - and it will be integrated into other (free) software too.

7-zip is under a GPL based license. It may not be sold in any form without prior arangement from the writers of all algorythms involved. And it's source may not be used/included in any closed source program period. Is this program using it as a loadable module? That is the only method I am aware of that such a program can make use of 7-zip.

No. You download a "zipzag.exe", after installing there's a "7-zip32.dll" in the program folder. Thanks for telling - I'll drop a note in 7-zip forum.

[EDIT] Done. BTW I noticed that a new beta has been released today:
[/EDIT]

edit: correction - (and look down ) 7-Zip is LGPL'd, i thought it's GPL'd.

Apparently the 7zip dll is LGPL'ed, so this is not illegal.

Even if it were GPL, you'd still be completely wrong.

I don't claim to be a GPL expert garf. You very well could be right. So then I ask you for some clarrification.

Suppose I developed a software under the GPL license. Any software directly incorporating my code must also use a GPL license. Am I correct so far?

Now I am contacted by a third party interested in using my code in a software that does not use a GPL license. It is my perogative as the author to allow or deny the use of my code under a different license. A license which could include those used for pay software. Or is that wrong?

When it comes to GPL code that incorporates other authors GPL code I can not release my code if it depends on theirs under any license other than GPL. That is unless I were to get their permission. And in turn if they were to get permission form authors of other GPL code they might have used. And so on and so forth. Or is that incorrect?

Yup. The bit you missed is the bit in the GPL that lets you sell GPL'd software.



Heck, RMS himself made a living selling GNU software for a while.

Garf may have also been picking up on your choice of the word 'algorithm'. Algoithms are not copyrightable; only specific implentations are (see PGP vs GPG).

(Algorithms are, however, sometimes patentable. See GPG and why it can't use the IDEA algorithm ).

Aaaaaah. Yes my terminology was off. I see now where the issue is. So then outside of that though everything sounds kosher?

As far as packaging the DLL with pay software that should be ok as it is used as a load in module. But if it is in his installer he needs to provide info for 7-zip and where to find the source etc.

They provide no info at all. No source / link to the source. So this is a point with "possibility of improvement" to aviod violation of LGPL - right?

Yes, thanks to Peter Harris for clarifying me.



This is extremely unclear in the LGPL as far as I am concerned, relevant section:

B) Use a suitable shared library mechanism for linking with the Library. A suitable mechanism is one that (1) uses at run time a copy of the library already present on the user's computer system, rather than copying library functions into the executable, and (2) will operate properly with a modified version of the library, if the user installs one, as long as the modified version is interface-compatible with the version that the work was made with.

I'm not sure whether the installer counts as 'copying library functions into the exectuable', since the installer doesn't make use of them. I think this itself is not a violation in letter or spirit, but the LGPL also says:

You must give prominent notice with each copy of the work that the Library is used in it and that the Library and its use are covered by this License. You must supply a copy of this License. If the work during execution displays copyright notices, you must include the copyright notice for the Library among them, as well as a reference directing the user to the copy of this License.

And I gather from the comments here that this is not done.

To me that says it is ok to make use of the library if it is already on their system. But the words "already present" give me the impression that his packaging the library with his installer could be a no no. Especially as it seems he gives no legal info or info as where to find the source/project.

I don't think so, because it talks about not putting the library functions into the executable. Note that the next paragraph also talks about being able to replace the library. I think they just mean it must be clearly seperated from the .exe at runtime. In any case it is extremely unclear what exactly is meant.

It is unclear I agree. But one thing I think is clear. It seems he should provide legal and contact info for 7-zip and other stuff he has included with his program.

Another free compression utility using 7-zip:

IZArc.

Homepage, not working here ATM
German mirror

Main advantage IMO: Easy conversion from any archive to 7-zip.

Latest 7-zip libs: http://cgi23.plala.or.jp/~a-w-h/cgi-bin/do...oad.cgi?7-zip32