Is it allowed to embed an LGPL command-line tool?

Question

I want to sell a closed-application that depends upon a certain command line tool. Am I allowed to distribute my software including this command line tool?

For example, as a separate binary accompanied by the proper NOTICE file and if needed the source code.

Do I need to explain how I call this binary, so the user could swap it?

Answer 1

Do consult a lawyer for this, anything you get from this site (such as the answer that follows) will not free you from any liability nor guaranteed that you will be safe from prosecution. This site is most definitively NOT a proper replacement for any sort of legal advice.

Now to the matter at hand, from what I understand, LGPL will allow inclusion of a licensed library if the user of your proprietary software can replace, on his own, the LGPL components with his own. This implies that either you used it directly without modifications or provide the source code with your modifications to the component and that you provide sufficient means for the customer to perform the modifications.

In other words the LGPL must guarantee that the customer remains free to do whatever it pleases to the LGPL covered parts that are shipped with your application without going though you first.

The wikipedia page is a pretty good place to get started to understand this http://en.wikipedia.org/wiki/GNU_Lesser_General_Public_License

you could try browsing groklaw see if they covered the subject

http://www.groklaw.net/index.php

Again this is NOT legal advice in anyway do get yourself a lawyer to help you through this properly.

Thanks to GpN to fin this FAQ that pretty much covers what you are looking for.

Answer 2

LGPL allows you to link or embed binaries without opening your own source, so long as you provide the source code for the binaries and publish any changes you make to the libraries.

You must also deploy your application in a way that allows someone to replace the LGPL'd library, if they so choose. In practice, this means that you must dynamically link to the library, so that a compiler and your source code are not required to perform the linking.

Answer 3

The text of the LGPL is complex, as it attempts to define the term 'link', since the LGPL is intended to cover libraries. So it's a completely open legal question as to whether incorporating an LGPL executable (which is not a library) as part of a larger work is:

1. the creation of a derivative work exempted from GPL provisions by the LGPL.
2. the creation of a derivative work not exempted from GPL provision by the LGPL.
3. the creation of a 'mere aggregation', and so not subject to the terms of the license at all.

It would depend on how a court decided to construe the exemption in the LGPL and how that same court would view what you've constructed. It may depend on exactly, technically, how you combine that executable with the rest of your stuff.

In case (1) or (3), you only have to make the source of the command itself available. In (2), you'd have to make all your source available.

In short, if there's a lot of money on the line here, you'll need legal advice.

Answer 4

AFAICT it is not forbidden to sell (L)GPLed software, as long as you provide a way to get its source; e.g. Red Hat does exactly this. I assume you don't make any modifications to the (L)GPLed tool, so linking to the canonical source code should be fine.

It looks like the tool is specifically designed to be included as a part of a non-GPL derived work. At least, so it works for LGPL libraries that you can link to a non-GPL binaries.

Note: IANAL.