I want to use a dictionary (basically a text file, and no code) that is included with an open office spell checking plug-in. The plug-in is under the tri-license GPL/LGPL/MPL which I don't understand. is that legal?

If it is illegal, what if I wrote a script that uses the said open office plug-in to generate the dictionary (assuming it's technically possible, the script will generate all possible letter permutations, passes it to the plug-in and saves the correct ones) ?

I will be using the dictionary in a closed source commercial application.

The dictionary is in a language that has very little resources online, and short of making my own dictionary, there aren't any alternatives.

Clarification: The script idea I mentioned above, isn't a weird technique, I would generate a document with all possible words and use open office with the plug-in installed to show spelling mistakes and remove them, isn't this the intended use of the plug-in (spell checking)?

  • Can you provide a link to the licence that the plug-in (and thus presumably the dictionary file) uses? Apr 27, 2013 at 15:50
  • There isn't any.. there's only a read-me file that says: "The dictionary is under three licences: GPL/LGPL/MPL".
    – rad
    Apr 27, 2013 at 18:28
  • how do you intend to distribute your application? What do you mean by closed source commercial app? Apr 27, 2013 at 19:35

2 Answers 2


Code can be released under multiple licenses.

If you don't have permission to use the original file and you "launder" it like you're suggesting, you aren't really changing anything. Judges aren't dumb, so if you're essentially hoping that copying it in a weird way will make it legal when copying it directly would not, stop thinking that.

Also, don't think that "otherwise, I'd have to make my own" will fly.

It's possible that there is something available on the internet that is not specific to your language but that you could use. It's also possible that the code and the data file for the plugin you're talking about are under different licenses.

  • Thank you Michael, I'm also wondering how does GPL/LGPL/MPL work? AFAIK, using something released under GPL means I have to provide source code for my application, and using something released under LGPL means I can use it in a closed source application if I use it unmodified, and I don't know much about MPL, so how would the three licenses apply combined? unless I misunderstood and different parts of the plug-in are under different licenses, which seems unlikely since I can't find anywhere that mentions which parts are under which license.
    – rad
    Apr 27, 2013 at 18:43
  • 2
    Multiple licensing works because the person USING the library (that's you) gets to pick which of the available licenses to use it under. So, for a commercial app, you can still use the code by using it under the LGPL (read the LGPL itself for details). Now, if you are only using part of it, then stripping it down might be considered a modification, and you'd have to release the modified code (but not the rest of your code). Jun 26, 2013 at 20:17

There are two possible scenarios, with different consequences for the licensing position.

  1. Your application reads the dictionary as an input file. Your application does not care where the dictionary comes from as long as it is in the right format. Providing the dictionary along with your application is essentially a convenience for your users, if they want they can just replace it.

    In this case, it does not really matter what license the dictionary has, as long as you are allowed to re-distribute (which all free licenses allow, that's an essential part of them being free), because the combination of your application and the dictionary will not be considered a derived/modified work, but rather an aggregation of independent works.

  2. Your application links to the dictionary like using a software module.

    • If you link statically (the end-user can't replace the dictionary with a different version without recompiling), you are most likely out of luck and your closed-source application can't be distributed. It might be that the MPL allows it, but I am not familiar enough with it to tell.
    • If you link dynamically (the end-user can replace the dictionary with a different version without recompiling), then you can use the dictionary under the terms of the LGPL. Because the dictionary is multi-licensed, you get to choose which license terms you want to apply.

In all cases, it should be clear that the dictionary and your application are distributed under different licences and where the source for the dictionary can be obtained (unless the dictionary file itself is its source).

  • Thank you, the triple-license thing makes sense to me now.
    – rad
    Apr 27, 2013 at 19:06

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