Blogging Roller quotes Ed Burnette:

If you really want to ensure true freedom of your code, put it under the control of a Foundation like Apache or Eclipse. Foundations are not controlled by any one company so you can feel comfortable about being on a level playing field with your competitors.

Unless one company starts giving disproportionate sums to the foundation - and most foundations are not going to turn away money. You can see this in the political sphere - plenty of charitable foundations have entirely different political orientations from their (now deceased) founders, because they were "captured" by generous funding.

If you think that can't happen in the business world, you're simply naive.