<html><body><span style="font-family:Verdana; color:#000000; font-size:10pt;"><div>Greetings,<br><br>As per the Open Source Definition, commercial use of Open Source software must be permitted, yet "the license shall not require a royalty or other fee for such sale."<br><br>One interesting side-effect of the above is that software can be released under a strong copyleft license, for instance the GPL, and yet be accompanied by the option to "buy one's way out of the license," thereby releasing the buyer from any and all obligation to make the modified source available to the public. For a possible real-life example please see the cygwin project, and specifically the clause concerning the project license (found under "Cygwin License Contract" at <a href="http://www.redhat.com/services/custom/cygwin">http://www.redhat.com/services/custom/cygwin</a>/, and mentioned here for illustration purposes only).<br><br>In light of the above, and given the guarantee of the Open Source Definition with respect to source availability and fields of endeavor, a couple of questions arise:<br><br>1) to what extent does the GPL meet the OSI promise regarding the source of Open Source Software remaining open? After all, if vendors can take GPL'ed software and buy their way out of the license so that binaries, with or without changes, can be distributed without restriction and without a corresponding source, then something is probably not working the way it was originally intended.<br><br>2) Consider the case of an individual entrepreneur who created a software library, and who would like to require vendors of commercial products that _depend_ on that library to pay a _one-time fee_, but otherwise be permitted to use the library or distribute it in any way they see fit without additional charges, and provided that the original source code, along with all changes that were applied to it, remain available to the public. Would that author be able to release his/her library under an OSI-approved license? Having gone through the various licenses on the site, I was unable to identify a single license that adequately meets this scenario.<br><br>I believe that (2) could be of interest to independent developers who either prefer not to, or are unable to rely on voluntary donations for the continuing development of their projects. Then again, it seems to me that the possibility to regulate one-time charges for commercial use from _within_ a license should be much preferred over a de facto option to bypass the license altogether. Ultimately, then, the purpose of this post is to discuss, and hopefully find out, whether a license can be written with the above scenario in mind, and yet remain in compliance with the Open Source Definition.<br><br>Looking forward to your thoughts,<br>z. gilboa<br><br></div></span></body></html>