Quicklisp has become the main way many (most?) people handle installing a library for Common Lisp. Under the hood, ASDF is used for defining the system and specifying how it should be compiled and such as has also been standard in the community for a very long time.
Yeah, this is correct. ASDF and Quicklisp are essentially pervasive in the Common Lisp community now.
If you see a library you want to use, like the HTTP client drakma, then you just start your Lisp and write
(ql:quickload "drakma")
and it will download it (if needed), install it (if needed), compile it (if needed), and load it. It's really easy, and completely changed the game for Lisp about 15 years ago.
Quicklisp has become the main way many (most?) people handle installing a library for Common Lisp. Under the hood, ASDF is used for defining the system and specifying how it should be compiled and such as has also been standard in the community for a very long time.