Licensing question

Nov 25, 2010 at 11:08 PM


Honestly I think that I will never understand completely GPL/LGPL (and so) licenses.

I'm building a commercial application and want to use only the local hook engine of EasyHook.

Is legal to take some of the .c files and add them into my .dll project? I'm not modifying any code, only converting the portions I need of EasyHook into a library to be used in my dll.

And, if it is ok, what kind of copyright banner should I add in order to mention EasyHook usage?

Best regards,
Mauro H. Leggieri

Dec 14, 2010 at 6:52 PM

Sorry for the late response. I got more requests of this kind so I put an explaination on the main page.

No you are not allowed to do so. You may only use EasyHook in its binary form. After all as long as exactly point out that you are using EasyHook for example as a visible "Powered-By"-Banner and you just directly link with the c files it seems fine to me. But it is still a breach with the LGPL but I wouldn't mind in this particular case, as long as the product you are creating is not something like EasyHook.


Dec 14, 2010 at 7:09 PM

Hi Chris,

Don't worry and thank you for your answer.

I am making an app that records audio conversations from skype and uses EasyHook to hook waveIn/waveOut api's. Because it is a dll, instead of having 2 separate libraries, the only thing I want to do is to compile the local hook routines of EasyHook in the same project. I have no problem in adding the "powered-by" banner.

I ask you because understanding usage of GPL/LGPL and that kind of licenses gives me headaches :)


Jan 7, 2011 at 3:17 PM

I found a small issue with your license description on the front page.

This is the only GPL/LGPL type discussion that I found, and I didn't want to create a new topic, so....

You mention that one can not use the GPL and/or LGPL code in a commercial application.  This is technically incorrect.  One may charge money for an application that is subject to GPL/LGPL licensing; however, he must also release the source code for that application.  In practice, this is very difficult, because someone with the technical expertise and motivation can take your source code and provide an alternative at no cost.

What most people do that legally make money off of open source projects is to add binary-separate (closed-source) enhancements, or offer support and service which can not be easily duplicated.

btw:  I am quite anxious to try out EasyHook in my own application...looks very promising.