Dependencies are software libraries and tools that a piece of software requires to be present in order to function. Dependencies provide ready-to-use functionality but, as their name indicates, they are also liabilities. They take up space in memory, but perhaps more importantly, they can become inaccessible or change in incompatible ways, making the dependent piece of software difficult or even impossible to use.
If you choose to use HyperDoc, it becomes a dependency of your code. And HyperDoc's dependencies become your indirect dependencies. You should thus know what these dependencies are.
HyperDoc is implemented as two ASDF systems: