diff --git a/meson.build b/meson.build
index 1690bb50a..356d978dc 100644
--- a/meson.build
+++ b/meson.build
@@ -11,6 +11,8 @@ subproject('libstore')
 subproject('libfetchers')
 subproject('libexpr')
 subproject('libflake')
+subproject('libmain')
+subproject('libcmd')
 
 # Docs
 subproject('internal-api-docs')
diff --git a/packaging/components.nix b/packaging/components.nix
index e9e95c028..f1cd3b9c6 100644
--- a/packaging/components.nix
+++ b/packaging/components.nix
@@ -28,6 +28,10 @@ in
   nix-flake = callPackage ../src/libflake/package.nix { };
   nix-flake-tests = callPackage ../tests/unit/libflake/package.nix { };
 
+  nix-main = callPackage ../src/libmain/package.nix { };
+
+  nix-cmd = callPackage ../src/libcmd/package.nix { };
+
   nix-internal-api-docs = callPackage ../src/internal-api-docs/package.nix { };
   nix-external-api-docs = callPackage ../src/external-api-docs/package.nix { };
 
diff --git a/packaging/hydra.nix b/packaging/hydra.nix
index 97f2c59b7..0bbbc31f7 100644
--- a/packaging/hydra.nix
+++ b/packaging/hydra.nix
@@ -51,6 +51,8 @@ let
     "nix-expr-tests"
     "nix-flake"
     "nix-flake-tests"
+    "nix-main"
+    "nix-cmd"
   ];
 in
 {
diff --git a/src/libcmd/.version b/src/libcmd/.version
new file mode 120000
index 000000000..b7badcd0c
--- /dev/null
+++ b/src/libcmd/.version
@@ -0,0 +1 @@
+../../.version
\ No newline at end of file
diff --git a/src/libcmd/meson.build b/src/libcmd/meson.build
new file mode 100644
index 000000000..d9a90508a
--- /dev/null
+++ b/src/libcmd/meson.build
@@ -0,0 +1,126 @@
+project('nix-cmd', 'cpp',
+  version : files('.version'),
+  default_options : [
+    'cpp_std=c++2a',
+    # TODO(Qyriad): increase the warning level
+    'warning_level=1',
+    'debug=true',
+    'optimization=2',
+    'errorlogs=true', # Please print logs for tests that fail
+  ],
+  meson_version : '>= 1.1',
+  license : 'LGPL-2.1-or-later',
+)
+
+cxx = meson.get_compiler('cpp')
+
+subdir('build-utils-meson/deps-lists')
+
+configdata = configuration_data()
+
+deps_private_maybe_subproject = [
+]
+deps_public_maybe_subproject = [
+  dependency('nix-util'),
+  dependency('nix-store'),
+  dependency('nix-fetchers'),
+  dependency('nix-expr'),
+  dependency('nix-flake'),
+  dependency('nix-main'),
+]
+subdir('build-utils-meson/subprojects')
+
+nlohmann_json = dependency('nlohmann_json', version : '>= 3.9')
+deps_public += nlohmann_json
+
+lowdown = dependency('lowdown', version : '>= 0.9.0', required : get_option('markdown'))
+deps_private += lowdown
+configdata.set('HAVE_LOWDOWN', lowdown.found().to_int())
+
+readline_flavor = get_option('readline-flavor')
+if readline_flavor == 'editline'
+  editline = dependency('libeditline', 'editline', version : '>=1.14')
+  deps_private += editline
+elif readline_flavor == 'readline'
+  readline = dependency('readline')
+  deps_private += readline
+  configdata.set(
+    'USE_READLINE',
+    1,
+    description: 'Use readline instead of editline',
+  )
+else
+  error('illegal editline flavor', readline_flavor)
+endif
+
+config_h = configure_file(
+  configuration : configdata,
+  output : 'config-cmd.hh',
+)
+
+add_project_arguments(
+  # TODO(Qyriad): Yes this is how the autoconf+Make system did it.
+  # It would be nice for our headers to be idempotent instead.
+  '-include', 'config-util.hh',
+  '-include', 'config-store.hh',
+  # '-include', 'config-fetchers.h',
+  '-include', 'config-main.hh',
+  '-include', 'config-cmd.hh',
+  language : 'cpp',
+)
+
+subdir('build-utils-meson/diagnostics')
+
+sources = files(
+  'built-path.cc',
+  'command-installable-value.cc',
+  'command.cc',
+  'common-eval-args.cc',
+  'editor-for.cc',
+  'installable-attr-path.cc',
+  'installable-derived-path.cc',
+  'installable-flake.cc',
+  'installable-value.cc',
+  'installables.cc',
+  'legacy.cc',
+  'markdown.cc',
+  'misc-store-flags.cc',
+  'network-proxy.cc',
+  'repl-interacter.cc',
+  'repl.cc',
+)
+
+include_dirs = [include_directories('.')]
+
+headers = [config_h] + files(
+  'built-path.hh',
+  'command-installable-value.hh',
+  'command.hh',
+  'common-eval-args.hh',
+  'editor-for.hh',
+  'installable-attr-path.hh',
+  'installable-derived-path.hh',
+  'installable-flake.hh',
+  'installable-value.hh',
+  'installables.hh',
+  'legacy.hh',
+  'markdown.hh',
+  'misc-store-flags.hh',
+  'network-proxy.hh',
+  'repl-interacter.hh',
+  'repl.hh',
+)
+
+this_library = library(
+  'nixcmd',
+  sources,
+  dependencies : deps_public + deps_private + deps_other,
+  prelink : true, # For C++ static initializers
+  install : true,
+)
+
+install_headers(headers, subdir : 'nix', preserve_path : true)
+
+libraries_private = []
+
+subdir('build-utils-meson/export')
diff --git a/src/libcmd/meson.options b/src/libcmd/meson.options
new file mode 100644
index 000000000..79ae4fa55
--- /dev/null
+++ b/src/libcmd/meson.options
@@ -0,0 +1,15 @@
+# vim: filetype=meson
+
+option(
+  'markdown',
+  type: 'feature',
+  description: 'Enable Markdown rendering in the Nix binary (requires lowdown)',
+)
+
+option(
+  'readline-flavor',
+  type : 'combo',
+  choices : ['editline', 'readline'],
+  value : 'editline',
+  description : 'Which library to use for nice line editing with the Nix language REPL',
+)
diff --git a/src/libcmd/package.nix b/src/libcmd/package.nix
new file mode 100644
index 000000000..5e6381a17
--- /dev/null
+++ b/src/libcmd/package.nix
@@ -0,0 +1,112 @@
+{ lib
+, stdenv
+, mkMesonDerivation
+, releaseTools
+
+, meson
+, ninja
+, pkg-config
+
+, nix-util
+, nix-store
+, nix-fetchers
+, nix-expr
+, nix-flake
+, nix-main
+, editline
+, readline
+, lowdown
+, nlohmann_json
+
+# Configuration Options
+
+, versionSuffix ? ""
+
+# Whether to enable Markdown rendering in the Nix binary.
+, enableMarkdown ? !stdenv.hostPlatform.isWindows
+
+# Which interactive line editor library to use for Nix's repl.
+#
+# Currently supported choices are:
+#
+# - editline (default)
+# - readline
+, readlineFlavor ? if stdenv.hostPlatform.isWindows then "readline" else "editline"
+}:
+
+let
+  inherit (lib) fileset;
+
+  version = lib.fileContents ./.version + versionSuffix;
+in
+
+mkMesonDerivation (finalAttrs: {
+  pname = "nix-cmd";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../build-utils-meson
+    ./build-utils-meson
+    ../../.version
+    ./.version
+    ./meson.build
+    ./meson.options
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
+
+  outputs = [ "out" "dev" ];
+
+  nativeBuildInputs = [
+    meson
+    ninja
+    pkg-config
+  ];
+
+  buildInputs = [
+    ({ inherit editline readline; }.${readlineFlavor})
+  ] ++ lib.optional enableMarkdown lowdown;
+
+  propagatedBuildInputs = [
+    nix-util
+    nix-store
+    nix-fetchers
+    nix-expr
+    nix-flake
+    nix-main
+    nlohmann_json
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  mesonFlags = [
+    (lib.mesonEnable "markdown" enableMarkdown)
+    (lib.mesonOption "readline-flavor" readlineFlavor)
+  ];
+
+  env = lib.optionalAttrs (stdenv.isLinux && !(stdenv.hostPlatform.isStatic && stdenv.system == "aarch64-linux")) {
+    LDFLAGS = "-fuse-ld=gold";
+  };
+
+  enableParallelBuilding = true;
+
+  separateDebugInfo = !stdenv.hostPlatform.isStatic;
+
+  # TODO `releaseTools.coverageAnalysis` in Nixpkgs needs to be updated
+  # to work with `strictDeps`.
+  strictDeps = true;
+
+  hardeningDisable = lib.optional stdenv.hostPlatform.isStatic "pie";
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})
diff --git a/src/libcmd/repl-interacter.cc b/src/libcmd/repl-interacter.cc
index eb4361e25..420cce1db 100644
--- a/src/libcmd/repl-interacter.cc
+++ b/src/libcmd/repl-interacter.cc
@@ -18,7 +18,7 @@ extern "C" {
 #include "finally.hh"
 #include "repl-interacter.hh"
 #include "file-system.hh"
-#include "libcmd/repl.hh"
+#include "repl.hh"
 
 namespace nix {
 
diff --git a/src/libcmd/repl.cc b/src/libcmd/repl.cc
index 53dd94c7a..ce1c5af69 100644
--- a/src/libcmd/repl.cc
+++ b/src/libcmd/repl.cc
@@ -3,7 +3,7 @@
 #include <cstring>
 #include <climits>
 
-#include "libcmd/repl-interacter.hh"
+#include "repl-interacter.hh"
 #include "repl.hh"
 
 #include "ansicolor.hh"
diff --git a/src/libmain/.version b/src/libmain/.version
new file mode 120000
index 000000000..b7badcd0c
--- /dev/null
+++ b/src/libmain/.version
@@ -0,0 +1 @@
+../../.version
\ No newline at end of file
diff --git a/src/libmain/meson.build b/src/libmain/meson.build
new file mode 100644
index 000000000..859ce22f8
--- /dev/null
+++ b/src/libmain/meson.build
@@ -0,0 +1,98 @@
+project('nix-main', 'cpp',
+  version : files('.version'),
+  default_options : [
+    'cpp_std=c++2a',
+    # TODO(Qyriad): increase the warning level
+    'warning_level=1',
+    'debug=true',
+    'optimization=2',
+    'errorlogs=true', # Please print logs for tests that fail
+  ],
+  meson_version : '>= 1.1',
+  license : 'LGPL-2.1-or-later',
+)
+
+cxx = meson.get_compiler('cpp')
+
+subdir('build-utils-meson/deps-lists')
+
+configdata = configuration_data()
+
+deps_private_maybe_subproject = [
+]
+deps_public_maybe_subproject = [
+  dependency('nix-util'),
+  dependency('nix-store'),
+]
+subdir('build-utils-meson/subprojects')
+
+
+pubsetbuf_test = '''
+#include <iostream>
+
+using namespace std;
+
+char buf[1024];
+
+int main() {
+  cerr.rdbuf()->pubsetbuf(buf, sizeof(buf));
+}
+'''
+
+configdata.set(
+  'HAVE_PUBSETBUF',
+  cxx.compiles(pubsetbuf_test).to_int(),
+  description: 'Optionally used for buffering on standard error'
+)
+
+config_h = configure_file(
+  configuration : configdata,
+  output : 'config-main.hh',
+)
+
+add_project_arguments(
+  # TODO(Qyriad): Yes this is how the autoconf+Make system did it.
+  # It would be nice for our headers to be idempotent instead.
+  '-include', 'config-util.hh',
+  '-include', 'config-store.hh',
+  '-include', 'config-main.hh',
+  language : 'cpp',
+)
+
+subdir('build-utils-meson/diagnostics')
+
+sources = files(
+  'common-args.cc',
+  'loggers.cc',
+  'progress-bar.cc',
+  'shared.cc',
+)
+
+if host_machine.system() != 'windows'
+  sources += files(
+    'unix/stack.cc',
+  )
+endif
+
+include_dirs = [include_directories('.')]
+
+headers = [config_h] + files(
+  'common-args.hh',
+  'loggers.hh',
+  'progress-bar.hh',
+  'shared.hh',
+)
+
+this_library = library(
+  'nixmain',
+  sources,
+  dependencies : deps_public + deps_private + deps_other,
+  prelink : true, # For C++ static initializers
+  install : true,
+)
+
+install_headers(headers, subdir : 'nix', preserve_path : true)
+
+libraries_private = []
+
+subdir('build-utils-meson/export')
diff --git a/src/libmain/package.nix b/src/libmain/package.nix
new file mode 100644
index 000000000..8c06fd004
--- /dev/null
+++ b/src/libmain/package.nix
@@ -0,0 +1,78 @@
+{ lib
+, stdenv
+, mkMesonDerivation
+, releaseTools
+
+, meson
+, ninja
+, pkg-config
+
+, nix-util
+, nix-store
+
+# Configuration Options
+
+, versionSuffix ? ""
+}:
+
+let
+  inherit (lib) fileset;
+
+  version = lib.fileContents ./.version + versionSuffix;
+in
+
+mkMesonDerivation (finalAttrs: {
+  pname = "nix-main";
+  inherit version;
+
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../build-utils-meson
+    ./build-utils-meson
+    ../../.version
+    ./.version
+    ./meson.build
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
+
+  outputs = [ "out" "dev" ];
+
+  nativeBuildInputs = [
+    meson
+    ninja
+    pkg-config
+  ];
+
+  propagatedBuildInputs = [
+    nix-util
+    nix-store
+  ];
+
+  preConfigure =
+    # "Inline" .version so it's not a symlink, and includes the suffix.
+    # Do the meson utils, without modification.
+    ''
+      chmod u+w ./.version
+      echo ${version} > ../../.version
+    '';
+
+  env = lib.optionalAttrs (stdenv.isLinux && !(stdenv.hostPlatform.isStatic && stdenv.system == "aarch64-linux")) {
+    LDFLAGS = "-fuse-ld=gold";
+  };
+
+  enableParallelBuilding = true;
+
+  separateDebugInfo = !stdenv.hostPlatform.isStatic;
+
+  # TODO `releaseTools.coverageAnalysis` in Nixpkgs needs to be updated
+  # to work with `strictDeps`.
+  strictDeps = true;
+
+  hardeningDisable = lib.optional stdenv.hostPlatform.isStatic "pie";
+
+  meta = {
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
+  };
+
+})