The GPL BusyBox license

There has been some confusion in the past as to exactly what is required to safely distribute GPL'd software such as BusyBox as part of a product. To ensure that there is no confusion whatsoever, this page attempts to summarize what you should do to ensure you do not accidentally violate the law.

Complying with the BusyBox license is easy and completely free.

U.S. and International Law protects copyright owners from the unauthorized reproduction, adaptation, display, distribution, etc of copyright protected works. Copyright violations (such as shipping BusyBox in a manner contrary to its license) are subject to severe penalties. The courts can award up to $150,000 per product shipped without even showing any actual loss by the copyright holder. Criminal penalties are available for intentional acts undertaken for purposes of "commercial advantage" or "private financial gain." In addition, if it comes to my attention that you are violating the BusyBox license, I will list you on the BusyBox Hall of Shame webpage.

Nobody wants that to happen. Do everyone a favor and don't break the law -- if you use BusyBox, you must comply with the BusyBox license.

BusyBox is licensed under the GNU General Public License

BusyBox is licensed under the GNU General Public License , which is generally just abbreviated as the GPL license, or just the GPL.

Anyone thinking of shipping BusyBox as part of a product should be familiar with the licensing terms under which they are allowed to use and distribute BusyBox. You are advised to take a look over the

to be sure you (and your lawyers) fully understand them.

The following is a quick summary for the impatient. If you carefully follow these steps, it will ensure that you are 100% authorized to ship BusyBox with your product, and have no reason to worry about lawsuits or being listed on the BusyBox Hall of Shame page. You will be able to sleep peacefully at night knowing you have fulfilled all your licensing obligations.

If you distribute a product, it should either be accompanied by full source for all GPL'd products (including BusyBox) and/or a written offer to supply the source for all GPL'd products for the cost of shipping and handling. The source has to be in its preferred machine readable form, so you cannot encrypt or obfuscate it. You are not required to provide full source for all the closed source applications that happen to be part of the system with BusyBox, though you can certainly do so if you feel like it. But providing source for the GPL licensed applications such as BusyBox is mandatory.

Accompanied by source generally means you distribute the full source code for all GPL'd products including BusyBox along with your product, such as by placing it somewhere on a driver CD. Full source code includes the BusyBox ".config" file used when your shipping BusyBox binary was compiled, and any and all modifications you made to the BusyBox source code.

A written offer generally means that somewhere in the documentation for your product, you write something like

The GPL source code contained in this product is available as a free download from http://blah.blah.blah/
Alternatively, you can offer the source code by writing somewhere in the documentation for your product something like
If you would like a copy of the GPL source code contained in this product shipped to you on CD, please send $9.99 to <address> which covers the cost of preparing and mailing a CD to you.

Keep in mind though that if you distribute GPL'd binaries online (as is often done when supplying firmware updates), it is highly recommended that you make the corresponding source available online at the same place. Regardless, if you distribute a binary copy of BusyBox online (such as part of a firmware update) you must either make source available online (i.e. accompanied by source) and/or inform those downloading firmware updates of their right to obtain source (i.e. a written offer). Failure to do so is a violation of your licensing obligations.

Some people have the mistaken understanding that if they use unmodified GPL'd source code, they do not need to distribute anything. This belief is not correct, and is not supported by the text of GPL. Please do re-read it -- you will find there is no such provision. If you distribute any GPL'd binaries, you must also make source available as discussed on this webpage.

A Good Example

These days, Linksys is doing a good job at complying with the GPL, they get to be an example of how to do things right. Please take a moment and check out what they do with distributing the firmware for their WRT54G Router. Following their example would be a fine way to ensure that you have also fulfilled your licensing obligations.