Are your Firefox extensions proprietary software?
1 June 2008
In the last-post, I went through the most popular Firefox extensions and talked about whether they were good ideas or not. However, it seems that not a lot of people think about another side to this, i.e. what are your Firefox extensions licenced under?
It turns out that a lot of the extensions available through Firefox are not free/open source software at all.
One example is the StumbleUpon Extension. StumbleUpon is a web service that allows you to share links with other users. Sometimes readers have shared this site and my number of visitors have gone up (cheers for that). StumbleUpon is commonly used through a toolbar provided as an extension through Firefox or Internet Explorer, (and a comment-in-the-last-post reminded me about it).
This made me think, what is the licence of this Firefox extension? If you go to the StumbleUpon-homepage, there is no software licence or terms at all. If you click the "Download now - Free" button, you go through to the download-page, still no licence or terms. I unzipped the extension, looking for a software licence, nothing. This made me very suspicious, when people are proud of their licence, they put it right in front of you, what are they hiding?
Eventually, after a bit of digging and Googling, I found their Toolbar-License and guess what? Yes you guessed it, it is proprietary software. So if you want to run free software/open source, then get it off your system now!
Their licence only gives you:
"a non-transferable ... non-sublicensable ... license to reproduce (solely to install and execute) the Toolbar on one of your computers, in executable object code format only, for your personal, non-commercial use only,"
Of course, the "Toolbar" is released as a Firefox extension, in plain-text Javascript and XUL, not in object code format. There is not really object code at all in Javascript, object code is a C term. But the lawyer writing the boilerplate probably didn't know or care about the difference. Anyhow, the licence continues:
"You may not modify, make derivative works of, copy, reproduce, publish, or reverse engineer the Toolbar"
This is in complete opposition to free software/open source, where all users have four freedoms:
- The freedom to run the program, for any purpose (freedom 0)
- The freedom to study how the program works, and adapt it to your needs (freedom 1). Access to the source code is a precondition for this.
- The freedom to redistribute copies so you can help your neighbor (freedom 2).
- The freedom to improve the program, and release your improvements to the public, so that the whole community benefits (freedom 3). Access to the source code is a precondition for this.
Don't sell out your freedoms so cheaply! If you want the most free software computer possible, look up the licenses of your extensions.
For example, here are five popular extensions that are free software/open source:
- Firebug: Mozilla Public License 1.1
- Flashblock: Mozilla Triple Licence (MPL 1.1/GPL 2.0/LGPL 2.1)
- AdblockPlus: Mozilla Public License 1.1
- FireGPG: Mozilla Triple Licence (MPL 1.1/GPL 2.0/LGPL 2.1)
- NoScript: GPL
Please do audit your own, and let us know what you find. Knowing which extensions are free and which are not free would be really helpful.



1 zxcopiedfromirc says...
It's a difficult problem. Even when people get bitten by proprietary stuff they don't seem to realise what's going on. So they happily line up to buy the next shiny thing.
Posted at 3:23 a.m. on June 1, 2008
2 Jonas says...
I don't understand why they do not use a free license really. Okay, I sometimes can see why a proprietary license would feel more palatable for the people in charge (I disagree with the reasoning but I can see how they're thinking) but only when their product is softare. While the toolbar certainly is software it is the service that is valuable. And even more silly when the source code is, by definition in this case, is included to begin with.
Posted at 3:36 a.m. on June 1, 2008
3 gregf says...
Wow, I really never gave this much though till I saw your title. Maybe if a bunch of users talked to the Firefox developers, they could be convinced in warning users they are about to install software without a open source compatible license? Or is that even something they should or would be worried about?
Posted at 5:21 a.m. on June 1, 2008
4 NickF says...
Not surprising. If you install Skype on Windows it automatically install a firefox plugins, even if you say no. You can uninstall it, but it comes back at every update. The same for RealPlayer, which is worse because you can't uninstall it. Having proprietary addons is not the problem, but having them forced down on you, that is really where the problem is
Posted at 9:36 a.m. on June 1, 2008
5 Ubu Walker says...
If I download an extention from the Firefox website (which is open source), I expect, unless told otherwise, that it is open source.
Posted at 5:16 p.m. on June 1, 2008
6 Anurag says...
As most of my extensions are provided by Ubuntu's Add/Remove, they are opensource anyways...
Posted at 6:26 p.m. on June 1, 2008
7 Emily says...
Ubu Walker said: If I download an extension from the Firefox website (which is open source), I expect, unless told otherwise, that it is open source.
You may expect that, I may have expected that, but it is not true. The Firefox website just puts them up without license information, free and non-free extensions are all mixed in together.
Posted at 11:35 p.m. on June 1, 2008
8 Steven says...
Being open source is nice, but whats better is code that works. If there are two weather plug-ins, one works, the other doesn't, and the one that works is proprietary but still works, I'll take it. They're both free. Let the guy horde his code, I don't care. He has neither hurt nor helped the "movement."
nVidia > ati but nVidia != open source... still use nVidia, oh well!
Posted at 5:22 a.m. on June 2, 2008
9 Max says...
@Steven -
Let the guy horde his code, I don't care. He has neither hurt nor helped the "movement."
He hasn't hurt the free software movement, but you have. You just showed your support for his proprietary software.
Posted at 10:02 p.m. on June 2, 2008
10 Morten Juhl-Johansen Zölde-Fejér (mjjzf) says...
Anurag said: As most of my extensions are provided by Ubuntu's Add/Remove, they are opensource anyways... Now, how did you arive at that conclusion?
Anyway, Flashblock may be entire free software, but as yet it isn't much needed without a certain item of very proprietary software.
Posted at 7:53 a.m. on June 3, 2008
11 db0 says...
Anyway, Flashblock may be entire free software, but as yet it isn't much needed without a certain item of very proprietary software.
you mean like Gnash?
Posted at 11:56 a.m. on June 3, 2008
12 mithrandir says...
No, Swfdec...
Posted at 4:02 p.m. on June 3, 2008
13 dwr50 says...
If I get something from the Firefox site I expect it to be open source and virus free... it's a given. If Firefox endorses the program, that's good enough for me.
Posted at 10:47 p.m. on June 4, 2008
14 Steve Purkiss says...
I'm in a slightly different position - I've created a sidebar for the video conversation site http://seesmic.com - you can find it at http://seesmicsidebar.com and the code at http://code.google.com/p/seesmic-sidebar/
So you can get the code for my extension, but not for the service I provided it for - seesmic. They're very much a closed community and of course have all your data/videos too.
I'm hoping that some project will start up which does cool stuff like video conversations, but open source and where the application is data-unaware, i.e. I don't have to give all my data to BigCo (or soon-to-be-BigCo).
Trouble is, it seems all the free software developers are focusing on re-implementing what's already out there and not creating cool new stuff. If I knew more about Flash and decentralised networking then I'd do it myself. But then Flash isn't open. Bugger. When will it end?! ;)
Posted at 11:15 p.m. on June 4, 2008
15 Craig says...
Here's a thought: I don't recall ever being asked to agree to a EULA before downloading a Firefox add-on. Maybe I just haven't downloaded any proprietary ones, but I think if they don't even require you to click "I Accept" on a click-through EULA, there's no way they can claim that you're bound by a license. Simply installing software, by itself, cannot be reasonably construed to indicate that you accept a license that you are never shown or asked to agree to. (They can say otherwise, but I doubt it would hold up in court.)
Posted at 11:25 p.m. on June 4, 2008
16 Swashbuckler says...
"object code is a C term."
Uh no. It's any compiled language.
Posted at 10:26 p.m. on June 5, 2008
17 Orlandus says...
Well, if they offer only an object-code-only license.and no object code, then I suppose nobody is legally entitled to have the software at all.
Posted at 11:54 p.m. on June 9, 2008
18 vermin says...
> Eventually, after a bit of digging and Googling, I found their Toolbar-License...
You simply found the license of the StumbleUpon Toolbar for Internet Explorer. This is another product, much more common than the FF toolbar. It indeed does not include any source code.
Posted at 3:32 a.m. on July 7, 2008
19 paul21 says...
Shame on Mozilla. They should make developers specify the extension license before hosting it. They should show the license next to download button as well.
Posted at 6:19 a.m. on July 10, 2008
20 Kiki says...
Would be useful if the mozilla extension repository had a license value in their extension entries instead of having to do my own very lengthy research instead of doing real work.
Posted at 3:56 a.m. on September 26, 2008
21 Timo Juhani Lindfors says...
Just for your info, there's a bug report titled "make licensing information available about add-ons" at https://bugzilla.mozilla.org/show_bug.cgi?id=446361
Posted at 11:28 a.m. on September 29, 2008
22 Ano says...
"You simply found the license of the StumbleUpon Toolbar for Internet Explorer."
That's possible. I've got some more interesting information to add. Firstly, go to this page: https://addons.mozilla.org/en-US/firefox/addon/138 - this is the actual Firefox addon.
Scrolldown and notice 'Mozilla Public License, version 1.1' - confusing! So, is this Firefox toolbar governed by the 'Mozilla Public License, version 1.1' and the IE toolbar governed by http://www.stumbleupon.com/terms.html or is the 'Mozilla Public License, version 1.1' somewhat compatible with their own license (see the actual Mozilla license, and scroll down to the last bit showing mention of another possible license in the exhibit)? It would be great to get some clarification...
Another interesting thing is that when you search for 'stumble toolbar' in Google, and then click on the shortcut link to download the toolbar (using firefox) it goes to http://www.stumbleupon.com/download.php which auto-redirects you to the Mozilla Firefox addon site. If you try the same in IE, it ends up with a 'do you want to install the IE toolbar' page. I.e. the page is auto-selecting/redirecting.
Interesting discussion....
Posted at 8:24 p.m. on October 27, 2009