Problem about licence and copyright, worry me more than learning a new language

[ZeodoHokill]

hi everyone,

I am a new firefox extension developer and just start build my first
firefox extension, I recently develop something that make firefox act
more like google browser.

So all my code done, but before I submit I decide to have a check on
copy right problem, that worry me.

My addon is actually base on two current work. First, I actually copy
and modified some XBL code from firefox tabbrowser.xml. Secondly, my
addon depends on another addon - ChrominFrame by Zero Fire (https://
addons.mozilla.org/en-US/firefox/addon/10091).

I go through the document, and find that firefox with tri-licence and
ChrominFrame is MPL.

I wonder what so I do explicitly in order to obey the licence (for
example, what comment should I include in my code), and since my work
do not include code frame ChrominFrame but instead change it by XBL,
should I also attach MPL header to my work, with original developer as
Zero Fire.

Sorry I am really new in Open Source Contribution, my English is
really bad and I get headache when facing legal problem. I mean no
offense to any rule, I just wanna to contribute to Firefox I love. So
could anyone give me some advice on it?

Thank you very much

[Frank Hecker]

ZeodoHokill wrote:
> So all my code done, but before I submit I decide to have a check on
> copy right problem, that worry me.

We are not lawyer, and so cannot give you formal legal advice. However I
can give you my opinion.

> My addon is actually base on two current work. First, I actually copy
> and modified some XBL code from firefox tabbrowser.xml.

If you copied code from an existing file that is under the MPL/GPL/LGPL
trilicense, then your source code file (or files) that contain that code
must be under the trilicense as well. In other words, your source code
files that contain the copied code should also contain a copy of the
original license notices from the files where the code originated.

> Secondly, my
> addon depends on another addon - ChrominFrame by Zero Fire (https://
> addons.mozilla.org/en-US/firefox/addon/10091).

Could you clarify this? Do you mean that your extension requires
Chrominframe to be already installed on the user's system?

> I wonder what so I do explicitly in order to obey the licence (for
> example, what comment should I include in my code), and since my work
> do not include code frame ChrominFrame but instead change it by XBL,
> should I also attach MPL header to my work, with original developer as
> Zero Fire.

This depends on whether you copied source code from ChrominFrame, or are
simply depending on it to be installed separately. Please see my
question above.

Frank

--
Frank Hecker
hec...@mozillafoundation.org

[ZeodoHokill]

Thanks Frank Hecker, seem I need to copy the licence header from the
file.
About my dependence with ChrominFrame, I just invoke some function
provide by it and also reference to some id of it, I didn't copy any
code from ChrominFrame. In MPL it is clear that if I copy/modify some
code I need to state in licence header, but it is not clear what to do
if I just reference to other's code.

[Frank Hecker]

ZeodoHokill wrote:
> About my dependence with ChrominFrame, I just invoke some function
> provide by it and also reference to some id of it, I didn't copy any
> code from ChrominFrame. In MPL it is clear that if I copy/modify some
> code I need to state in licence header, but it is not clear what to do
> if I just reference to other's code.

If you are just calling ChrominFrame code (and not actually including
ChrominFrame code in your own source files) then the MPL license on the
ChrominFrame code does not affect the license you can choose for your
own code.

However if you distribute the ChrominFrame code as part of your overall
extension then you need to satisfy the MPL requirements for the
Chrominframe code, including notifying people that source code is
available for ChrominFrame and telling them where to find the source code.

Frank

P.S. The usual disclaimer: I am not a lawyer, this is not legal advic, etc.

--
Frank Hecker
hec...@mozillafoundation.org

[ZeodoHokill]

Thank You very much, I know what to do now

[Jean-Marc Desperrier]

Frank Hecker wrote:
> If you copied code from an existing file that is under the MPL/GPL/LGPL
> trilicense, then your source code file (or files) that contain that code
> must be under the trilicense as well. In other words, your source code
> files that contain the copied code should also contain a copy of the
> original license notices from the files where the code originated.

Sorry Franck, whilst it doesn't change much to your answer to
ZeodoHokill, I believe you are not properly describing it here.

Mozilla has a policy that code that is contributed back for integration
in the tree must be trilicensed.

But the point of trilicensing is that people who just use the code in
their own project have the right to use any one of the three license, or
any combination they want of them.

So people who release their project under the GPL licence can include
mozilla files as GPL only, and thus not worry about possible
incompatibilities between GPL and MPL.

[Frank Hecker]

Jean-Marc Desperrier wrote:
> Mozilla has a policy that code that is contributed back for integration
> in the tree must be trilicensed.
>
> But the point of trilicensing is that people who just use the code in
> their own project have the right to use any one of the three license, or
> any combination they want of them.
>
> So people who release their project under the GPL licence can include
> mozilla files as GPL only, and thus not worry about possible
> incompatibilities between GPL and MPL.

You're correct. I was simplifying the situation for ease of explanation.