Some of them need to be rewritten, some other are completely useless now, because of dA's evolution.
This thread is meant to share the links toward Firefox Extensions working with dA v5.
It's obvious that they have to be exclusively created, and distributed freely by deviants on deviantart.com.
Here are those that are working so far.
DeviantLink Browser Extension
That's all I found, normally bluespeed9 should be enhancing his deviantSkin extension for dA v.