Wikipedia yog ib qho piv txwv zoo ntawm kev pabcuam tsis muaj kev lag luam. Lawv muab online encyclopedia thiab tsis xav tau dab tsi rov qab. Kuv tsis tas yuav muab nyiaj kom nkag mus rau Wikipedia, Kuv tsis tas yuav pauv kuv cov ntaub ntawv, saib xyuas lossis lwm yam, txij li lawv tsis muaj trackers lossis tshaj tawm. ntawm course they need money to sustain themselves in this trade-based world, but they make this voluntary in the form of donations. So if you can and want to support them, you can do so, if not, then you don’t have to – you will still have access to Wikipedia.

I think that’s the closest TF service as it can be, and it’s always one of the main examples. It’s collaborative, educative, and reliable resource used by the whole world. They don’t have ads, and also have a policy about NOT advertising. They run by donations.