Firstly, is there a legal difference between simply linking to the libraries (e.g. hosted by the project owners) and distributing an unmodified version (still containing the license) on my site's server?
Secondly, how do I manage the licensing? Do I have to include an explicit "Licensing" page on the website linking to all the dependencies or are the comments in the code sufficient?
If I am understanding the situation correctly, the mere use of a GPLv3 library binds me to make the project open source. The other licenses do not seem to require such a thing. They however require a certain reproduction of the license notice, and I am wondering what is considered as a "notice".