diff --git a/pkgs/servers/irc/inspircd/default.nix b/pkgs/servers/irc/inspircd/default.nix
new file mode 100644
index 00000000000..f1df10514e6
--- /dev/null
+++ b/pkgs/servers/irc/inspircd/default.nix
@@ -0,0 +1,218 @@
+let
+  # inspircd ships a few extra modules that users can load
+  # via configuration. Upstream thus recommends to ship as
+  # many of them as possible. There is however a problem:
+  # inspircd is licensed under the GPL version 2 only and
+  # some modules link libraries that are incompatible with
+  # the GPL 2. Therefore we can't provide them as binaries
+  # via our binary-caches, but users should still be able
+  # to override this package and build the incompatible
+  # modules themselves.
+  #
+  # This means for us we need to a) prevent hydra from
+  # building a module set with a GPL incompatibility
+  # and b) dynamically figure out the largest possible
+  # set of modules to use depending on stdenv, because
+  # the used libc needs to be compatible as well.
+  #
+  # For an overview of all modules and their licensing
+  # situation, see https://docs.inspircd.org/packaging/
+
+  # Predicate for checking license compatibility with
+  # GPLv2. Since this is _only_ used for libc compatibility
+  # checking, only whitelist licenses used by notable
+  # libcs in nixpkgs (musl and glibc).
+  compatible = lib: drv:
+    lib.any (lic: lic == drv.meta.license) [
+      lib.licenses.mit        # musl
+      lib.licenses.lgpl2Plus  # glibc
+    ];
+
+  # compatible if libc is compatible
+  libcModules = [
+    "regex_posix"
+    "sslrehashsignal"
+  ];
+
+  # compatible if libc++ is compatible
+  # TODO(sternenseemann):
+  # we could enable "regex_stdlib" automatically, but only if
+  # we are using libcxxStdenv which is compatible with GPLv2,
+  # since the gcc libstdc++ license is GPLv2-incompatible
+  libcxxModules = [
+    "regex_stdlib"
+  ];
+
+  compatibleModules = lib: stdenv: [
+    # GPLv2 compatible dependencies
+    "argon2"
+    "ldap"
+    "mysql"
+    "pgsql"
+    "regex_pcre"
+    "regex_re2"
+    "regex_tre"
+    "sqlite3"
+    "ssl_gnutls"
+  ] ++ lib.optionals (compatible lib stdenv.cc.libc) libcModules;
+
+in
+
+{ lib
+, stdenv
+, fetchFromGitHub
+, fetchpatch
+, perl
+, pkg-config
+, libargon2
+, openldap
+, postgresql
+, libmysqlclient
+, pcre
+, tre
+, re2
+, sqlite
+, gnutls
+, libmaxminddb
+, openssl
+, mbedtls
+# For a full list of module names, see https://docs.inspircd.org/packaging/
+, extraModules ? compatibleModules lib stdenv
+}:
+
+let
+  extras = {
+    # GPLv2 compatible
+    argon2 = [
+      (libargon2 // {
+        meta = libargon2.meta // {
+          # use libargon2 as CC0 since ASL20 is GPLv2-incompatible
+          # updating this here is important that meta.license is accurate
+          license = lib.licenses.cc0;
+        };
+      })
+    ];
+    ldap            = [ openldap ];
+    mysql           = [ libmysqlclient ];
+    pgsql           = [ postgresql ];
+    regex_pcre      = [ pcre ];
+    regex_re2       = [ re2 ];
+    regex_tre       = [ tre ];
+    sqlite3         = [ sqlite ];
+    ssl_gnutls      = [ gnutls ];
+    # depends on stdenv.cc.libc
+    regex_posix     = [];
+    sslrehashsignal = [];
+    # depends on used libc++
+    regex_stdlib    = [];
+    # GPLv2 incompatible
+    geo_maxmind     = [ libmaxminddb ];
+    ssl_mbedtls     = [ mbedtls ];
+    ssl_openssl     = [ openssl ];
+  };
+
+  # buildInputs necessary for the enabled extraModules
+  extraInputs = lib.concatMap
+    (m: extras."${m}" or (builtins.throw "Unknown extra module ${m}"))
+    extraModules;
+
+  # if true, we can't provide a binary version of this
+  # package without violating the GPL 2
+  gpl2Conflict =
+    let
+      allowed = compatibleModules lib stdenv;
+    in
+      !lib.all (lib.flip lib.elem allowed) extraModules;
+
+  # return list of the license(s) of the given derivation
+  getLicenses = drv:
+    let
+      lics = drv.meta.license or [];
+    in
+      if lib.isAttrs lics || lib.isString lics
+      then [ lics ]
+      else lics;
+
+  # Whether any member of list1 is also member of list2, i. e. set intersection.
+  anyMembers = list1: list2:
+    lib.any (m1: lib.elem m1 list2) list1;
+
+in
+
+stdenv.mkDerivation rec {
+  pname = "inspircd";
+  version = "3.9.0";
+
+  src = fetchFromGitHub {
+    owner = pname;
+    repo = pname;
+    rev = "v${version}";
+    sha256 = "0x3paasf4ynx4ddky2nq613vyirbhfnxzkjq148k7154pz3q426s";
+  };
+
+  patches = [
+    # Remove at next release, makes --prefix and --system work together
+    (fetchpatch {
+      url = "https://github.com/inspircd/inspircd/commit/b378b5087b41f72a1624ebb58990180e0b0140aa.patch";
+      sha256 = "0c0fmhjbkfh2r1cmjrm5d4whcignwsyi6kwkhmcvqy9mv99pj2ir";
+    })
+  ];
+
+  nativeBuildInputs = [
+    perl
+    pkg-config
+  ];
+  buildInputs = extraInputs;
+
+  preConfigure = ''
+    patchShebangs configure make/*.pl
+    # configure is executed twice, once to set the extras
+    # to use and once to do the Makefile setup
+    ./configure --enable-extras \
+      ${lib.escapeShellArg (lib.concatStringsSep " " extraModules)}
+  '';
+
+  configureFlags = [
+    "--disable-auto-extras"
+    "--distribution-label" "nixpkgs${version}"
+    "--system"
+    "--uid" "0"
+    "--gid" "0"
+    "--prefix" (placeholder "out")
+  ];
+
+  postInstall = ''
+    # installs to $out/usr by default unfortunately
+    mv "$out/usr/lib" "$out/lib"
+    mv "$out/usr/sbin" "$out/bin"
+    mv "$out/usr/share" "$out/share"
+    rm -r "$out/usr"
+    rm -r "$out/var" # only empty directories
+    rm -r "$out/etc" # only contains documentation
+  '';
+
+  enableParallelBuilding = true;
+
+  meta = {
+    description = "A modular C++ IRC server";
+    license = [ lib.licenses.gpl2Only ]
+      ++ lib.concatMap getLicenses extraInputs
+      ++ lib.optionals (anyMembers extraModules libcModules) (getLicenses stdenv.cc.libc)
+      # FIXME(sternenseemann): get license of used lib(std)c++ somehow
+      ++ lib.optional (anyMembers extraModules libcxxModules) "Unknown"
+      # Hack: Definitely prevent a hydra from building this package on
+      # a GPL 2 incompatibility even if it is not in a top-level attribute,
+      # but pulled in indirectly somehow.
+      ++ lib.optional gpl2Conflict lib.licenses.unfree;
+    maintainers = [ lib.maintainers.sternenseemann ];
+    # windows is theoretically possible, but requires extra work
+    # which I am not willing to do and can't test.
+    # https://github.com/inspircd/inspircd/blob/master/win/README.txt
+    platforms = lib.platforms.unix;
+    homepage = "https://www.inspircd.org/";
+  } // lib.optionalAttrs gpl2Conflict {
+    # make sure we never distribute a GPLv2-violating module
+    # in binary form. They can be built locally of course.
+    hydraPlatforms = [];
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index ccde125fc37..edae119c244 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -18229,6 +18229,10 @@ in
     theme-spring = callPackage ../servers/icingaweb2/theme-spring { };
   };
 
+  inspircd = callPackage ../servers/irc/inspircd { };
+
+  inspircdMinimal = inspircd.override { extraModules = []; };
+
   imgproxy = callPackage ../servers/imgproxy { };
 
   ircdog = callPackage ../applications/networking/irc/ircdog { };