Qt now also licensed under the LGPL

[Lashiec]

I held onto posting this since I expected Ehtyar would mention it in his weekly news report, but he did not so here it is.

Since Nokia bought Trolltech last year, Qt has seen significant improvements in many areas that have made the toolkit even more interesting to work with. Despite this, the licensing terms governing its usage made difficult for many developers to use it in their projects as the available options meant they either had to open source the software in order to comply with the GPL and thus be able to use the free edition, or to pay a significant sum of money for the commercial license.

But with the release of Qt 4.5, Nokia will introduce a new licensing option: the LGPL. Technicalities aside, this means developers of non-commercial closed source projects will be able to finally use Qt without having to open the source code of its software. Commercial developers also can take advantage of the new licensing terms to use Qt without paying a cent, but their freedom to develop the software is more constrained and it lacks certain support options.

Another important change is that Trolltech will open a public repository containing the Qt code, which in turn will make more easier for other people to review and enhance the toolkit.

Qt 4.5 also includes other nice new features, like better integration of Qt-based apps in GNOME desktops. Information page about the new license, analysis at Ars Technica and discussion at Slashdot

So, mouser, about that cross-platform FARR...
via Ars Technica and [url=http://slashdot.org/]Slashdot

[gexecuter]

I wonder how long Mouser would take to completely rewrite FAAR into QT, 2, 4 or 6 months? rewriting a program into a whole different language seems a lot of work.

[Lashiec]

Nah, I wasn't really serious, but the idea was hurled around a while ago. But yeah, it would take a lot of time, despite it's not really using a new language.

But if we consider that mouser was thinking into rewriting FARR, well...

[mahesh2k]

Nokia Is spreading its tentacles across software world by  purchasing Symbian & Trolltech, they're in both Mobile and Desktop market now.

I wonder how long Mouser would take to completely rewrite FAAR into QT, 2, 4 or 6 months? rewriting a program into a whole different language seems a lot of work.

If most of us on DC starts to develop using Cross-platform toolkits then i'm sure we'll make more linux/mac users happy with software.

[mouser]

This is pretty significant news regarding QT.  It's a high-quality, actively developed set of libraries, that had until now pretty restrictive licensing terms.  This definitely makes it more feasible to use QT in projects which are wary of having all of their code open sourced.

Let's not forget that WxWidgets is also an extremely well developed cross-platform library that has long been available.  So now there are two really good choices for (C++ especially, and other) programmers wanting to develop cross platform tools.

Cool news.  I think it would be useful now to see some up to date detailed comparisons of wxWidgets vs Qt.

[Ehtyar]

I passed over Qt in favor of wxWidgets as wx had a simpler API, far more stl-like than Qt, and Qt (were you not paying for the library, and even then there is no pricing system) was using the tyrianical GPL. Perhaps this will improve adoption of Qt in the open source community.

As to why it wasn't included in my weekly, I didn't actually know about it :S I obviously need a few more software-centric feeds in my reader...any suggestions?

Ehtyar.

[Ehtyar]

Oh it's not officially out yet. I try to avoid news for 'planned' or 'anticipated' things anyway, but if people have stories they think should be included, feel free to PM me.

Don't know how I missed it on ARS...weird.

Ehtyar.

[mouser]

I try to avoid news for 'planned' or 'anticipated' things anyway

amen to that!

i'm sick of companies trying to double up on the press releases and publicity by announcing something once well ahead of any planned action, and then again once they "actually" do it. 

[Ehtyar]

Trouble is, quite often the major press acknowledges the 'anticipation' release, then completely ignored the 'actual' release. Of course the companies that pull that kind of crap deserve to the have the final launch ignored, so I suppose it doesn't matter much.

Ehtyar.

[CWuestefeld]

I know of a number of top-quality applications that employ Qt; hopefully with this change more will be able to join these ranks.

On the other hand, it seems to me that gobbledygook like this

• We will continue to support the GPL version 2 through the newly added LGPL version 2.1 license, as it allows for the automatic conversion to the GPL.
• We will continue to release Qt under GPL 3

As a first step we have selected LGPL version 2.1 as this is the version of the LGPL that best fits our purposes and we are most comfortable with at this point in time.

It seems to me that all of this nonsense with the shades of legal meaning between different licenses (not to mention their versions!) do nothing to improve the "freedom" of software. Quite the opposite, the explosion of licenses and the confusion they cause, multiplied by uncertainty of their real legal implications, actually chills the use of open software. I know that I've been chased away from using open source software because I was concerned about licensing legalities.

The open source community seems to have realized this recently, but it's far too late to fix. Efforts to clarify things by introducing new version numbers adds to the problem rather than cutting through the confusion.

[mouser]

I believe, and i'm no expert on these things, that the significant difference in moving Qt from GPL to LGPL is that you can now use the Qt library in a closed source (or whatever) application, as long as you make open source any changes you make to the Qt library itself.

In the past, under a GPL license, if you used Qt in your application, your application essentially also became entirely GPL open source.

That may not be exactly right but i think that's the basic gist of it.  Maybe others can correct anything i got wrong.

[Ehtyar]

Yes, provided you dynamically link the the LGPL'd code. If you want to use static linking, you must at least provide the object files of your application so that they may be linked against a newer version of the LGPL'd library. Sillyness.

Ehtyar.

[f0dder]

Yes, provided you dynamically link the the LGPL'd code. If you want to use static linking, you must at least provide the object files of your application so that they may be linked against a newer version of the LGPL'd library. Sillyness.

-Ehtyar (January 19, 2009, 12:49 AM)

Yeah, that's lame - some people fortunately add a "static-linking-is-OK" clause, though