The thought is about monetizing free software. In the traditional sense, free
software relies on donations, a big company willing to give their code away
for free, or creating custom software for a company. That is totally
understood.
With having your libraries and core software as free software, you are
already being generous for giving away the source code for your hard work so
someone can take that and do what they want with it. Especially if you
weren't paid or making any profit in creating that core software
Let's say you create this core software and 5 companies hire you to create a
software application. By having the core application in a permissive license
you are able to give them peace of mind that they wont have to release ALL of
the code for final product due to a license like the GPL while still having
that core software compatible with the GPL.
On top of that you may have a free library that connects to MySQL but didn't
have the time or resources to have one that connects to Postgres or Oracle.
Maybe you didn't want to pay a license to Oracle. Whatever. That could be the
situation where you create a plugin for Oracle and offer it as a seperate
paid for and proprietary plugin that you charge the consumer for since they
are the exception.
I'm seeing it where the majority of the customers will use the free software
but when something beyond that is needed, you create it and make it non-free
without comprimising the original core application due to it being a plugin
and that non-free component isn't included or even talked about in the one
you host on Github.
