I was asked this question in many scenarios. Well, here’s the answer. This blob does not intend to have a compare between GPL and BSDL, which is extensively discussed in many places, and basically, GPLers and BSDers all have what the counterpart could not accept.

Simply put, GPL is somewhat too complex and I suspect whether everyone is supposed to read it carefully and obey it. On the other hand, BSDL is simple, which, as a sample, is:

/*-
* Copyright (c) [year] [your name]
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS’’ AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* [id for your version control system, if any]
*/

More simpler, the main idea of a BSD licence is, “Fell free to use my software, never sue me, never claim that’s created by you”. GPL will deprive more freedom from potential contributors because “Once you got your code derived under GPL, you have to distribute it under GPL”.

Many big companies ban their employees from touching GPL’ed code because it may cause their product to be GPL’ed, which, in general, is not acceptable for a commercial company. In other words, it’s okay for everyone to contribute to open source if they are licenced with a looser licence, like LGPL, BSDL, MIT Licence, etc, but GPL will stop many of them.

And, if you want open source, why do not let the commercial companies to use it?

Let me quote something from this article:

“One of the most ridiculous reasons for adopting the GPL is…“oh but if Microsoft takes my code…”, well, what makes you think they will? I understand they bought and paid their own TCP/IP stack, even when the free BSD version was available; they simply didn’t want to give credit to anyone. If they take your code and do significant improvements everyone wins, if they don’t do any significant improvements the resulting product will probably not sell well, and people can still get your sources; no one will “take away” free software from you.”

Speaking as a student learning computer science, I believe that the most important thing for a software will *never* be the source code itself. Well, it’s something laypeople will stick with. The most important thing is the design, which is mostly protected by patents, not copyright, nor something like GPL. BSD will make more people to be able to adopt your code, and improve human life, that’s good and enough if you really want an “Open Source” to benefit others.