There is already a Javascript implementation [1], but it is not feasible to setup a full IPFS node in every browser tab that loads an IPFS resource. Instead you can use ipfs-companion [2], a browser extension that lets you easily load IPFS resources in your browser. While it can use the Javascript implementation, this is not recommended as it is currently pretty resource heavy [3].
Does the "deliverying JS to browser" thing that I described make sense at all?