Many free-educational-content projects don't seem to live up to the expectations, have a restrictive license, or fail to make significant progress, but this issue is too important to ignore.
Proposal
Setup a multi-lingual wiki
Remark: Right now there are no "out of the box" solutions for a wiki as a proper "build to end product" tool. A wiki is okay for source code but far from okay for the end result.
We create a top-level structure covering all the elementary school areas, which we fill with (donated or self-written) courses.
Recital: please explain a bit more in human readable output
We start contacting elementary schools and/or their associations to see help identify areas for which they need better education material
Recital: focussing on a group where the chance to get succesful in higher is smart to do. Basicaly every form of special, niche education is an interesting field. But creating awareness in main stream education is a must.
We don't want to be dependent on government funds (or government funded organisations) to reach our goals, but they are very welcome to help.
We need specify how they can help us (financially, technically and socially). Just like how free software got started by RMS.
It is believed we should create a good educational content service first (with feedback from the schools), and then start to lobby for more attention and financial support. It is also believed that the mediawiki approach is crucial. Seems a chicken egg problem on the other hand because we don't get 1 penny from governments, so everything we do (i.e. hard working people) is in our spare time.