Any JS that runs in the browser runs in Deno, too - so that's quite a few libraries...
If there is a Node-specific library, i.e. a lib that uses the require global, the fs module, etc., then you can, in many cases, use the Node compat module from the Deno std lib and just drop it into your project.
That being said, there's of course a Deno-specific ecosystem of libs, too, i.e. libs that use the Deno global. So you might find a suitable replacement if your favorite Node lib is not compatible for some reason.
If there is a Node-specific library, i.e. a lib that uses the require global, the fs module, etc., then you can, in many cases, use the Node compat module from the Deno std lib and just drop it into your project.
That being said, there's of course a Deno-specific ecosystem of libs, too, i.e. libs that use the Deno global. So you might find a suitable replacement if your favorite Node lib is not compatible for some reason.