These useful tips can help you locate some common issues when releasing software that contains code under the GNU GPL licence. For a complete and authoritative guide to releasing software under the GNU GPL you should read the FSF's GNU GPL FAQ and the FSF's HOW-TO for using the GNU GPL.
This is not legal advice. If you have doubts consult a legal advisor.
Basic guidelines:
- Check if the source code of the software is available to users.
- Check if you are the copyright holder of the software and if you include Free Software copyrighted by third parties make sure you give proper credit.
- Check if you are distributing the correct version of the source code. The source code shipped must be the same source code used to build the binary.
- Check if you include the source code for any derivative works of the GNU GPL code you are using, not just of the third-party GNU GPL components themselves.
- Check if you include the scripts used to control compilation and installation.
- If the toolchain is released and contains tools under the GNU GPL (like the GCC compiler), check if the source code for those tools is also released.
Before shipping the product:
- Check if your purchasing contracts require suppliers to disclose the presence of any GPL software.
- Check if your suppliers provide all the materials you need to comply with the GNU GPL licence.
- It helps to ensure that if your supplier turns out to not comply with the GPL they agree to rectify the situation in a timely fashion.
Shipping the product:
- Check if a copy of the GNU GPL licence is shipped with the product.
- Check if a copy of the source code is shipped with the product or that you include a written offer to provide the source code on a physical media like a CD ROM for no more than the cost of production and shipping.
- Remember you cannot offer a download link to the source code instead of a written offer to ship the source code on physical media. You can supplement the written offer with a reference to a download site. This may reduce the number of requests for source code.
- Remember that if you distribute binaries over the Internet you must host the source code on a server that you operate or that is operated by someone you have an explicit arrangement with.
Don't forget to review the FSF's HOW-TO for using the GNU GPL. It's short, clear and explains exactly what you need to do when you release code under the GNU GPL licence.
ที่มา - FSFE