Hello, On Apr 2 15:49 Olaf Meeuwissen wrote (shortened): > ... the epkowa backend does not require the non-free extensions.
As far as I understand the license stuff, this is the crucial condition whether or not some piece of software can be under GPL even if it "uses" some non-free additional module. The epkowa backend is useful for many scanners without the non-free extensions. Therefore is does not necessarily "link" with non-free stuff. Therefore it is a stand-alone-usable free software. Therefore it can be under GPL. This license issue is another item why drivers (backends) and applications (frontends) should be better isolated from each other. Currently frontends link with libsane which links with libdriver which may link with libdrivermodule which is only clean GPL if all parts are under the same GPL version. But as soon as there are differnt licenses (from incompatible free software licenses up to proprietary software licenses) the mess starts. If the frontend would not link with libsane but talk to saned via whatever protocol and if saned would not link with libdriver but talk to the driver via whatever protocol, every part could be under whatever license. Of course such a loose coupling is perfect for any kind of non-free drivers and non-free frontends ;-) But another big advantage of such a loose coupling is that broken drivers (aka. "non-free drivers" ;-) cannot hurt the rest of the scanning system (saned + frontend) provided the "whatever protocol" implementation is fail-safe: A few days ago I had accidentally messed up my SANE drivers with one broken driver which did a segfault. Because of the current linking, "scanimage -L" segfaults too regardless that I have several other scanners and drivers which could work well. > On a strictly personal note: I'd very much like to see those non-free > extensions to the epkowa backend become a thing of the past. Isn't the reason for non-free extensions often third-party licenses which make it impossible for the manufacturer to make a free driver even if he likes to do? For example printers which need a JBIG data compression to send printing data to the printer (so called ZJStream printers): JBIG data compression has patent issues which makes it impossible to make a free driver for ZJStream printers which is the reason why even HPLIP must use additional proprietary modules for certain printers, see for example https://bugzilla.novell.com/show_bug.cgi?id=342704 in particular https://bugzilla.novell.com/show_bug.cgi?id=342704#c1 and https://bugzilla.novell.com/show_bug.cgi?id=342704#c3 Of course very many users out there in the real world blindly buy ZJStream printers because they are cheap (i.e. get many dots per inch for less money ;-) and I guess it is the same for Epson scanners which require a non-free module which adds another layer to the whole problem: Should we repel such users ("you get what you paid for") and accept that Linux doesn't become very popular or should we swallow the bitter pill for the sake of making Linux more popular? My strictly personal opinion is: I accept optional additional non-free modules for free software (i.e. the non-free modules for the epkowa and hpaio drivers or for example the Adobe Reader plugin for free browsers) but I do not accept non-free software (i.e. which is useless without non-free stuff). Kind Regards Johannes Meixner -- SUSE LINUX Products GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany AG Nuernberg, HRB 16746, GF: Markus Rex
