A possible way, which don't requires direct financial, It's join the Hurd to contribute platforms. Currently, Hurd participates in Google Summer of Code.
But there are more platforms, like Outreachy or other similar, which allows to pay external contributors for makes a development in Free Software projects.
This could be more useful than a direct money financial, because It make easier to pay and manage to the developers in a legal way.
With direct money financial. can be difficult to pay the developer, because it's necessary to manage taxes, the job agreement it's difficult if the developer is foreign... etc.