RiveScript Licensing, Cont.

One of my friends started taking some classes to learn C++ recently and would ask me for some homework help now and then. I know much of the syntax of C++ pretty well due to the numerous times I've attempted to learn it by following tutorials, but this all inspired me to try diving back into it again.

On my many attempts to learn C++ I never actually made anything useful that wasn't a tutorial-like program (with the exception being a single-threaded CyanChat library I was working on but never completed). So this time I decided to just skip the tutorial b/s and dive right in to making a RiveScript C++ library, and Google things as I run into them.

I knew about C++ strings (who doesn't?) which are a big improvement over what C has, but I newly discovered vectors (dynamic resizable arrays) and maps (associative arrays) and among these three, it covers all the basic data types I'm used to in Perl.

I hit a roadblock though when it came to constructing the large data structure that the Perl RiveScript module makes and which I'm familiar with, but looking into C++'s struct solved that pretty quickly.

All this attention to RiveScript lately, though, made me remember the point about how the Perl RiveScript module (the only feature-complete implementation of RiveScript to date) is released under the GNU General Public License, which would demand that any application that uses it also be released under open source.

I was thinking of re-licensing RiveScript under a more open license to see if it could drive up usage of it for non-GPL projects. I was considering something like the LGPL, Apache or BSD license. But, I think I have a better idea!

At work I was using ExtJS for a while and I saw how their licensing scheme works: they dual-license their code; the GPL licensed version is free to use, but being GPL code it demands that your entire application be made open source. They then have a commercial license that allows you to use their library in a non-open application, for a fee.

I think this may be the better way to go. For the open source folks who use RiveScript today nothing changes, but if somebody wants to create a commercial application with RiveScript they wouldn't be able to use the GPL-licensed version. After watching all the news about SmarterChild and its parent company (Colloquis, now owned by Microsoft) over the past decade, with their chatterbot patent and their commercial SDK, giving out free code that can be used in a commercial closed-source product doesn't seem like a very smart move. ;)

The chatterbot patent now owned by Microsoft is groundless anyway, because the Net::AIM module on CPAN released in 1999 ships with an example script for an AIM chatterbot which pre-dates ActiveBuddy's inception in 2000. ActiveBuddy's claim that they invented the AIM chatterbot falls in the face of prior art.