diff --git a/.emacs.d/lisp/init-lisp.el b/.emacs.d/lisp/init-lisp.el
index 48c84220..d23744d6 100644
--- a/.emacs.d/lisp/init-lisp.el
+++ b/.emacs.d/lisp/init-lisp.el
@@ -151,10 +151,38 @@ returns a string."
   (advice-add 'sly-mrepl-next-prompt :override #'ambrevar/sly-mrepl-next-prompt)
   (advice-add 'sly-mrepl-previous-prompt :override #'ambrevar/sly-mrepl-previous-prompt)
 
-  (let ((dumper (expand-file-name "~/projects/lisp-repl-core-dumper/lisp-repl-core-dumper")))
+  (when (executable-find "lisp-repl-core-dumper")
     (setq sly-lisp-implementations
-          `((sbcl (,dumper "sbcl"))
-            (ccl (,dumper "ccl"))
+          `((sbcl ("lisp-repl-core-dumper" "sbcl" "ambrevar"))
+            ;; Simple REPL environment (no container):
+            (sbcl-nyxt ("guix" "environment" "--pure"
+                        "--preserve=^PERSONAL$" ; To find personal config, like engines and bookmarks.
+                        "-l" ,(expand-file-name "~/common-lisp/nyxt/build-scripts/guix.scm")
+                        "--ad-hoc" "gnupg" "--" "sbcl"))
+            (sbcl-nyxt-site ("guix" "environment" "--pure"
+                             "-m" ,(expand-file-name "~/common-lisp/nyxt-site/guix-manifest.scm")
+                             "--" "sbcl"))
+            ;; Faster, but not pure.  TODO: Can we purify it?  Run it in a container?
+            (sbcl-nyxt-fast
+             (lambda ()
+               ;; TODO: Replace root when source has changed?
+               (let ((root (expand-file-name "~/.guix-temp-profiles/nyxt")))
+                 (unless (file-exists-p root)
+                   (make-directory (file-name-directory root) :parents)
+                   (call-process "guix" nil nil nil
+                                 "environment" "--pure"
+                                 "--preserve=^PERSONAL$" ; To find personal config, like engines and bookmarks.
+                                 "-r" root
+                                 "-l" (expand-file-name "~/common-lisp/nyxt/build-scripts/guix.scm")
+                                 "--ad-hoc" "gnupg" "lisp-repl-core-dumper"
+                                 "--" "lisp-repl-core-dumper" "sbcl"))
+                 `(("bash" "-c" ,(concat
+                                  (format "source '%s/etc/profile'" root)
+                                  " && "
+                                  ;; TODO:
+                                  "lisp-repl-core-dumper sbcl"))))))
+            (ccl ("lisp-repl-core-dumper" "ccl"))
+            (clisp ("lisp-repl-core-dumper" "clisp"))
             (ecl ("ecl")))))
 
   (setq sly-connection-update-interval 0.1)
diff --git a/.package-lists/guix-nyxt-site-channels.scm b/.package-lists/guix-nyxt-site-channels.scm
deleted file mode 100644
index 4d94244d..00000000
--- a/.package-lists/guix-nyxt-site-channels.scm
+++ /dev/null
@@ -1,30 +0,0 @@
-(list (channel
-        (name 'nonguix)
-        (url "https://gitlab.com/nonguix/nonguix.git")
-        (commit
-          "7d555abb81f9f48edf333d7deedcb39f803e2d36")
-        (introduction
-          (make-channel-introduction
-            "897c1a470da759236cc11798f4e0a5f7d4d59fbc"
-            (openpgp-fingerprint
-              "2A39 3FFF 68F4 EF7A 3D29  12AF 6F51 20A0 22FB B2D5"))))
-      (channel
-        (name 'guix-gaming-games)
-        (url "https://gitlab.com/guix-gaming-channels/games.git")
-        (commit
-          "cfb3e76e6dbb52bd5e1605812020c0c01f8c08c4")
-        (introduction
-          (make-channel-introduction
-            "c23d64f1b8cc086659f8781b27ab6c7314c5cca5"
-            (openpgp-fingerprint
-              "50F3 3E2E 5B0C 3D90 0424  ABE8 9BDC F497 A4BB CC7F"))))
-      (channel
-        (name 'guix)
-        (url "https://git.savannah.gnu.org/git/guix.git")
-        (commit
-          "ae3c7e7d275a63b46dd5a7f04434871dfdd904ff")
-        (introduction
-          (make-channel-introduction
-            "9edb3f66fd807b096b48283debdcddccfea34bad"
-            (openpgp-fingerprint
-              "BBB0 2DDF 2CEA F6A8 0D1D  E643 A2A0 6DF2 A33A 54FA")))))
diff --git a/.package-lists/guix-nyxt-site-manifest.scm b/.package-lists/guix-nyxt-site-manifest.scm
deleted file mode 100644
index 6c9d7f54..00000000
--- a/.package-lists/guix-nyxt-site-manifest.scm
+++ /dev/null
@@ -1,25 +0,0 @@
-(specifications->manifest
-  '("gcc-toolchain"                    ; Needed to compile some Common Lisp FFI.
-    "sbcl"
-
-    "pandoc"
-    ;; "fcgi"
-    ;; "sqlite"
-
-    "sbcl-alexandria"
-    "sbcl-caveman"
-    "sbcl-clack"
-    "sbcl-datafly"
-    "sbcl-envy"
-    "sbcl-flexi-streams"
-    "sbcl-hunchentoot"
-    "sbcl-lack"
-    "sbcl-cl-ppcre"
-    "sbcl-ironclad"
-    "sbcl-cl-markup"
-    "sbcl-mito"
-    "sbcl-cl-project"
-    "sbcl-s-xml"
-    "sbcl-cl-str"
-    "sbcl-sxql"
-    "sbcl-uuid"))