> How would a free software project 'pay it forward'?
As mentioned by the grandparent comment, GPG is in use by Debian, Ubuntu and RedHat package managers. Whether or not you count those three as free software they have plenty of money to pay forward to a piece of software that underpins their entire stacks.
Unless I've missed something big in the past 2 years even the Debian Project Leader is still a volunteer[0]. If most/all money's going to operating costs it's hard to make the case they're holding out on somebody. They also have a record of treating their upstream quite well so I'd need some evidence to believe they're dropping the ball.
I am having a hard time to find financial statements from Debian.
Ubuntu, or rather Canonical, being a private company, doesn't seem to release financial information.
The Ubuntu main page doesn't even provide a 'donate' link anymore.
Which leaves RedHat, at last. A public company, of course[0]:
Operating profit 2014: $ 1.3e9
Net total income 2014: $ 178.3e6
This article claims that $222k was the budget for 2012 for Debian, down at the bottom. It also claims the budget should be $19B, if paid at market rates.
As mentioned by the grandparent comment, GPG is in use by Debian, Ubuntu and RedHat package managers. Whether or not you count those three as free software they have plenty of money to pay forward to a piece of software that underpins their entire stacks.