A requirement in the GNU GPL software license and other "free" software licenses that anyone who redistributes the software does so under the same license and also includes the source code. The "free" means free of restrictions (see free software). The copyleft clauses were written to support the copyright laws, not to eliminate them.
Strong Vs. Weak Copyleft
A "strong copyleft" license, such as the GNU GPL license, applies to all derived works, whereas a "weak copyleft" license, such as the GNU Lesser GPL, applies only to the copylefted work, not other components in the package. See GNU General Public License and copyright.
Strong Vs. Weak Copyleft
A "strong copyleft" license, such as the GNU GPL license, applies to all derived works, whereas a "weak copyleft" license, such as the GNU Lesser GPL, applies only to the copylefted work, not other components in the package. See GNU General Public License and copyright.
 | Reproduced with permission from Computer Desktop Encyclopedia. Copyright (c) 1981-2008 The Computer Language Company Inc. All rights reserved. |
Additional Resources
- Forbes rewrites the history of open source
- Forbes rewrites the history of open sourceI guess it was a political articleYou just convinced me that the purpose of this article in Forbes being written was to score political points. Which makes its rewriting of history doubly-disgusting.Libertarian?I'm pretty sure the GPL is normally associated with socialism, not libertarianism. Libertarians...
- Discussion threads 2008-08-18
- Android will be 100ò0open source, says Google
- Android will be 100ň0open source, says GoogleGoogle can't run from GPLGoogle need to create it own kernel, Googlix.looking forward to itso, will we finally be able to buy a phone at any store, and then sign up with mobile carriers solely for the sim card?RE: Android will be 100% open...
- Discussion threads 2008-06-02
- Google playing politics with open source
- Google playing politics with open sourceWell SaidI agree with this, Google has the same back office meetings that any other company does, and the main focus is selling more product and bringing the bling through the door. Both companies have their ups and downs and for us to act...
- Discussion threads 2008-03-18
- Does hardware need its own open source license?
- Slashdot reports that MIT has recently released some of its hardware designs under its own MIT license. (Pictured, Nick Negroponte as seen through an H.264 codec.) The license seems really good for this purpose because it says you can mess around with the hardware, but they're not warranting...
- Blog posts 2008-02-11
- Lawsuit asserts violation of GPL
- The Software Freedom Law Center will file its first lawsuit alleging violation of the GPL General Public License. The suit is against Monsoon Multimedia on behalf of the open-source BusyBox project. BusyBox is accusing Monsoon of failing to fulfill the license's copyleft obligations by including BusyBox in the firmware...
- Blog posts 2007-09-21
- It's over as SCO files for bankruptcy protection
- It's over as SCO files for bankruptcy protectionTrusteeNo trustee in sight (yet.) SCOXQ has petitioned the Court to allow the present management to continue to operate the company without any outside trustee being appointed. This is apparently quite common in Chapter 11 cases; it's only in Chapter 7...
- Discussion threads 2007-09-15
- Open source is apolitical
- Open source is apoliticalIs it?I suppose one can imagine anything, but the idea of a government at this point trying to outlaw the GPL seems incredible.After all, the GPL works in every country I'm aware of. Wouldn't that country risk an awful lot?Open Source is not a political entityAnyone can...
- Discussion threads 2007-08-24
- Google moves the numbers, press panics
- Google moves the numbers, press panicsThere is no such thing as the Apache BSD license.Apache has one license, BSD has another. They are not the same and you can check both to verify this.[url=http://www.opensource.org/licenses/bsd-license.php]BSD license[/url][url=http://www.apache.org/licenses/LICENSE-2.0]Apache license v.2[/url]There is no Apache BSD license.what is the role of proxies & specialized...
- Discussion threads 2007-08-07
- Microsoft establishes more anti-GPLv3 precautions
- Microsoft is running as fast as it can to patch up its patent agreements with Linux vendors to thwart any possible impact from the GPLv3.On the heels of repudiating any Novell Linux products covered by the GPLv3, Microsoft is taking a similar tack with Linspire, another of the Linux distribution...
- Blog posts 2007-07-18
- Intel aims to speed Linux gadget development
- Intel aims to speed Linux gadget developmentWyse Thin Clients; OLPCIntel has put on the good guy hat recently. Today they distance themselves further from HP and Microsoft. HP is now the largest tech company by revenue and has abandoned the HP way for the wrong ways of identity theft. ...
- Discussion threads 2007-07-16
- GPL 3 release set for Friday
- GPL 3 release set for FridayThis is going to be a very special moment in the history of Free Software.A big thanks to Richard Stallman, Eben Morgan, and all of the others working behind the scenes to make the GPL3 the best license on the planet. It will be very...
- Discussion threads 2007-06-28
- Top 5 myths of GPLv3 dispelled (part 1)
- Top 5 myths of GPLv3 dispelled (part 1)Top 5 what?You left out support. Give the software for free and sell support and.. service. Like development.Users need support and will gladly pay and do BTW.Isn't this a GPL issue in general?The issue of being able to sell GPL licensed...
- Discussion threads 2007-06-04
- FSF political discoloration
- FSF political discolorationIs the concentration on the code wise?If I have understood it correctly if someone took a piece of GPL'd code and then changed it and attempted to copyright it then they would be in breach of the GPL.If however they looked at the code (or observed the behaviour...
- Discussion threads 2007-05-30
- New GPLv3 draft takes aim at Microsoft/Novell but loosens crypto restrictions
- The Free Software Foundation FSF released the long-awaited third draft of the GNU General Public License GPL today. The draft was due out quite a bit earlier but was delayed after the Novell/Microsoft patent deal:We offer our apologies to the community for the delay in releasing Draft 3. Our original...
- Blog posts 2007-03-28
- European consumer chief targets iTunes
- European consumer chief targets iTunesDespite this notion being good for all...I fully expect the anti-EU sentiment to overshadow what is, essentially, the whole crux of the anti-DRM argument.she missing something ?Someone should tell her that you can burn songs purchased from iTunes to CD without any problems... and play it...
- Discussion threads 2007-03-12
- Time to short RedHat?
- Time to short RedHat?you missed listing Novell as a winneryou missed listing Novell as a winner.The proper question is who will be the loserAnd the answer is anyone who gets in bed with MICROSUCKS. As far as I am concerned this deal drives a stake through the heart of any...
- Discussion threads 2006-11-02
- Day 3: Stein: "In 5-10 years, most of the software you use will be free"
- (Greg Stein, chairman of the Apache Software Foundation, currently with Google, delivered this keynote on Wednesday morning at EclipseCon 2006. It was titled "Comparing Apache and Eclipse". -Ed) Jon Stevens is quoted as saying: "A license can ruin a perfectly good piece of software" One...
- Blog posts 2006-03-22
- GPL and definitions of freedom
- John Sullivan, a Program Administrator over at the FSF, responded to a previous blog post where I questioned whether the GPL really needs the ideals expressed by its authors in order to pursue the productivity advantages of a community development model. Not surprisingly, he argued that the GPL needs those...
- Blog posts 2006-02-24
- Wikipedia's open-source label conundrum
- Wikipedia's open-source label conundrumConfusing software with contentThis article appears to confuse the CONTENT of an application with the software that underlies the operation of the application. Wikipedia IS open-source software - no different from thousands of other open-source codeing efforts where contributions by CODERS of the project are strictly controlled...
- Discussion threads 2005-12-09
- Richard Stallman wants your help with GPL V3.0
- Richard Stallman wants your help with GPL V3.0Stallman's ego play....Last I heard Stallman was NOT invited, seems he didn't like it and has managed to wiggle his way back in.Oh yeah Bit?Would you care to document your statements?I don't agree completely with Stallman on everything but what you refer to...
- Discussion threads 2005-11-30
Neighboring Terms
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