However, John Mercouris has been developing Next Browser (originally styled nEXT Browser), a browser with a Common Lisp front-end, allowing for customisability and extensibility along Conkeror/Emacs lines:

The back-ends are – if I understand correctly – planned to be Blink for the QT port and WebkitGTK+ for the GTK port, with the Mac port of Webkit for the Mac version. But the front-end, the user-facing side, is Common Lisp.

John is currently running an Indiegogo campaign to properly port it to Linux and other non-Mac Unix variants (it apparently runs well already on the Mac, John’s main platform it seems [there’s no accounting for taste ;) ]). The raised money would be used in part to pay a professional C/C++ developer for their time.

Ambrevar is currently working on packaging Next Browser for Guix, which is exciting and promises to add to the amount of Lisp front-end software we’ll be able to use. Currently I’m running Emacs (elisp) for the majority of my non-browser productivity (writing papers & creating class slides using AUCTeX; reading composing email with mu4e; note-taking and scheduling with Org mode; &c. &c.) and, at least on one machine, StumpWM (Common Lisp window manager) for my ‘desktop environment’; and GNU GuixSD with a Guile-based package manager, Guile-based cron (mcron), and Guile-based init/daemon-manager (Shepherd). A functional, configurable, Lisp-based browser would be a most welcome addition. As excellent as Firefox is, especially its backend, I do really miss the halcyon days of Conkeror, and Next Browser could represent a return to those heady days of configurable browsing Emacs-style.

So, if this sort of thing appeals to you (i.e. if you like Lisp, Emacs, and/or highly-extendable browsers), you might want to support the Linux/Unix-port of Next Browser: https://www.indiegogo.com/projects/next-browser-nix-support

There’s only about a week left in the campaign.