Dated
You'll notice all the web pages are several years out of date. They're concepts that never got going because the engineering difficulties beat the apparent advantages.
You want to save 20% on fuel? - Build bigger jumbos.
Instead of filling the space with a giant hydrogen tank, fill it with passengers.
You want to save on emissions? - Use active control of engine combustion conditions.
You want better safety? - For God's sake don't even touch liquid hydrogen.
Planes fly and land every week with kerosene fuel leaks streaming out behind them (Die Hard notwithstanding). Planes that have an inflight emergency dump their fuel load safely.
You can't do that with H2.