I've been considering this for a long time, and have decided to switch to it at
the last minute before opening the repository up publicly. My reasons include:
* It's a much simpler license. GPL's complexity adds some risk - for example, it
might be incompatible with future open-source licenses (like the well-known
GPLv2/Apache v2 incompatibility problem). The "or any later version" clause
requires placing some trust in the Free Software Foundation.
* The simplicity makes it easier for people to understand and comply with the
license.
* Dishonest users who disobey the GPL would have an advantage over honest users
who refuse to do so. The ISC license provides a much more even playing field.
* OpenRS2 will primarily be server software accessible over a network. As such,
the GPL can do little to prevent use of the code in a proprietary system, as
the code is never distributed. (While the AGPL would fix this, I have already
discounted it. Enforcement would be too difficult and dishonest users would
have an unfair advantage.)
* It's much easier to switch to a stricter license in future versions, if it
turns out that is desirable (as the ISC license allows users to sublicense
the code). However, switching from the GPL to the ISC license requires all
copyright holders to grant permission.
* Other open-source projects in the community, such as Apollo, use the ISC
license and will be able to make use of OpenRS2 code if they so desire.
I've removed the FAQ entry about the reasons for using the GPL license, as I
think the ISC license is less controversial and therefore does not require an
entry.
I've discussed this with Desetude, and he's okay with his commit being
relicensed.
Graham