As someone who has tried to find a way to help content authors develop and maintain big web sites by creating (HTML) components for years, I\'m really excited to see web compone
In the current W3C spec there does not seem to be a specific way to define dependencies or even version them. Components are expected to not make use of any libraries/dependencies or to be tightly coupled with them.
This means that each major library will probably bring their own set of components with them that expect those libraries to have been loaded.
Maybe ES6 Modules provide help in this regard, but then again they currently also don't provide any versioning mechanisms.
That all said the spec is in a pretty early stage and is likely to change. Bringing the dependencies issue up with the spec authors might bring that topic to the table and might even solved before the spec solidifies. In the end using different libraries to perform the same task within a single code base has always been and will continue to be a problem in software development, regardless of platform and language. You will just have to agree upon which frameworks/libraries to use within your codebase, even if that means locking you out of others.
Also, if you are interested in developing independent components for the web already today you might want to take a look at the React library