when HP realized their webOS was going nowhere, they open sourced it to save a little face and gain a little goodwill, and then abandoned it.
It probably occurred to Toyota recently that hydrogen is not a good idea because:
1. hydrogen molecules are tiny and thus tend to leak out of everything
2. storing hydrogen is costly because of its low density (lowest in the universe) and the insanely cold temperatures required to liquify it
3. the chicken-and-egg problem of getting gas stations to carry it
According to the DC-X team (via Jerry Pournelle's blog) hydrogen is a very frustrating fuel to work with for reasons 1 and 2. Initially they were attracted to it for performance reasons (cryogenic fuel is the most powerful chemical rocket fuel in the universe) but after working with it for awhile came to the conclusion that kerosene/LOX was a far better choice from the standpoint of operational efficiency and cost. Lesson which SpaceX is using now to great effect.