diff --git a/pkgs/development/libraries/cosmopolitan/default.nix b/pkgs/development/libraries/cosmopolitan/default.nix
new file mode 100644
index 00000000000..629e5465a04
--- /dev/null
+++ b/pkgs/development/libraries/cosmopolitan/default.nix
@@ -0,0 +1,80 @@
+{ lib, gcc9Stdenv, fetchFromGitHub, runCommand, cosmopolitan }:
+
+gcc9Stdenv.mkDerivation rec {
+  pname = "cosmopolitan";
+  version = "0.3";
+
+  src = fetchFromGitHub {
+    owner = "jart";
+    repo = "cosmopolitan";
+    rev = version;
+    sha256 = "sha256-OVdOObO82W6JN63OWKHaERS7y0uvgxt+WLp6Y0LsmJk=";
+  };
+
+  postPatch = ''
+    patchShebangs build/
+    rm -r third_party/gcc
+  '';
+
+  dontConfigure = true;
+  dontFixup = true;
+  enableParallelBuilding = true;
+
+  preBuild = ''
+    makeFlagsArray=(
+      SHELL=/bin/sh
+      AS=${gcc9Stdenv.cc.targetPrefix}as
+      CC=${gcc9Stdenv.cc.targetPrefix}gcc
+      GCC=${gcc9Stdenv.cc.targetPrefix}gcc
+      CXX=${gcc9Stdenv.cc.targetPrefix}g++
+      LD=${gcc9Stdenv.cc.targetPrefix}ld
+      OBJCOPY=${gcc9Stdenv.cc.targetPrefix}objcopy
+      "MKDIR=mkdir -p"
+      )
+  '';
+
+  installPhase = ''
+    runHook preInstall
+    mkdir -p $out/{bin,lib/include}
+    install o/cosmopolitan.h $out/lib/include
+    install o/cosmopolitan.a o/libc/crt/crt.o o/ape/ape.{o,lds} $out/lib
+    cat > $out/bin/cosmoc <<EOF
+    #!${gcc9Stdenv.shell}
+    exec ${gcc9Stdenv.cc}/bin/${gcc9Stdenv.cc.targetPrefix}gcc \
+      -O -static -nostdlib -nostdinc -fno-pie -no-pie -mno-red-zone \
+      "\$@" \
+      -Wl,--oformat=binary -Wl,--gc-sections -Wl,-z,max-page-size=0x1000 \
+      -fuse-ld=bfd -Wl,-T,$out/lib/ape.lds \
+      -include $out/lib/{include/cosmopolitan.h,crt.o,ape.o,cosmopolitan.a}
+    EOF
+    chmod +x $out/bin/cosmoc
+    runHook postInstall
+  '';
+
+  passthru.tests = lib.optional (gcc9Stdenv.buildPlatform == gcc9Stdenv.hostPlatform) {
+    hello = runCommand "hello-world" { } ''
+      printf 'main() { printf("hello world\\n"); }\n' >hello.c
+      ${gcc9Stdenv.cc}/bin/gcc -g -O -static -nostdlib -nostdinc -fno-pie -no-pie -mno-red-zone -o hello.com.dbg hello.c \
+        -fuse-ld=bfd -Wl,-T,${cosmopolitan}/lib/ape.lds \
+        -include ${cosmopolitan}/lib/{include/cosmopolitan.h,crt.o,ape.o,cosmopolitan.a}
+      ${gcc9Stdenv.cc.bintools.bintools_bin}/bin/objcopy -S -O binary hello.com.dbg hello.com
+      ./hello.com
+      printf "test successful" > $out
+    '';
+    cosmoc = runCommand "cosmoc-hello" { } ''
+      printf 'main() { printf("hello world\\n"); }\n' >hello.c
+      ${cosmopolitan}/bin/cosmoc hello.c
+      ./a.out
+      printf "test successful" > $out
+    '';
+  };
+
+  meta = with lib; {
+    homepage = "https://justine.lol/cosmopolitan/";
+    description = "Your build-once run-anywhere c library";
+    platforms = platforms.x86_64;
+    badPlatforms = platforms.darwin;
+    license = licenses.isc;
+    maintainers = with maintainers; [ lourkeur tomberek ];
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 2b0c876113b..7cdaa42612a 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -13950,6 +13950,8 @@ in
 
   cog = callPackage ../development/web/cog { };
 
+  cosmopolitan = callPackage ../development/libraries/cosmopolitan { };
+
   ctl = callPackage ../development/libraries/ctl { };
 
   ctpp2 = callPackage ../development/libraries/ctpp2 { };