I was traveling from Zurich to Frankfurt, and when I asked a tourist information, the guy advised that the best way is train. I took the train, and when arrived in Frankfurt, I found that there is a German company having bus from Zurich to Frankfurt with 1/3 of the train price.
The problem is that bus companies are small and not-connected. On the other hand, such small companies have website mainly in their local languages (not English). As a result, it is difficult for a foreigner to find the best option for bus from a country to another; particularly, as they operate from small stations rather than a big united terminal (as one can go and ask for options).
Are there resources (e.g., websites) for searching all bus routes around Europe?