diff --git a/build_config/host-shared.rb b/build_config/host-shared.rb
index 76e3a0713..9eaef55f2 100644
--- a/build_config/host-shared.rb
+++ b/build_config/host-shared.rb
@@ -1,36 +1,94 @@
-# NOTE: Currently, this configuration file does not support VisualC++!
-#       Your help is needed!
+# Build mruby with a shared libmruby.so (in addition to the usual
+# libmruby.a / executables).
+#
+# Produces (in build/host/lib/):
+#   libmruby.a              the static archive (as in the default build)
+#   libmruby.so             the shared library, with SONAME=libmruby.so.<MAJOR>.<MINOR>
+#   libmruby.so.<MAJOR>.<MINOR>  symlink to libmruby.so (matches SONAME)
+#   libmruby.map            linker version script (MRUBY_<RELEASE_NO>)
+#
+# Also produces the matching libmruby_core.so + symlink for completeness.
+#
+# Symbol versioning ties to MRUBY_RELEASE_NO (e.g. MRUBY_40000 for 4.0.0).
+# mruby has historically had ABI breaks between TEENY versions, so the
+# version tag uses the full release number rather than just MAJOR.MINOR.
+#
+# The shared library is built FROM the static archive via
+# `-Wl,--whole-archive`, so the existing static-build pipeline (including
+# the test infrastructure) is unaffected.  Executables in build/host/bin
+# remain statically linked; distros that want dynamically-linked
+# executables can rebuild them against the .so.
+#
+# NOTE: gcc/clang only — VisualC++ support requires a separate config.
+
+require "mruby/source"
 
 MRuby::Build.new do |conf|
-  # load specific toolchain settings
   conf.toolchain
 
   # include the GEM box
   conf.gembox 'default'
 
-  # C compiler settings
+  # -fPIC so the static archive's contents can be linked into the .so.
   conf.compilers.each do |cc|
     cc.flags << '-fPIC'
   end
 
-  conf.archiver do |archiver|
-    archiver.command = cc.command
-    archiver.archive_options = '-shared -o %{outfile} %{objs}'
-  end
-
-  # file extensions
-  conf.exts do |exts|
-    exts.library = '.so'
-  end
-
-  # file separator
-  # conf.file_separator = '/'
-
-  # enable this if better compatibility with C++ is desired
-  #conf.enable_cxx_exception
-
   # Turn on `enable_debug` for better debugging
   conf.enable_debug
   conf.enable_bintest
   conf.enable_test
 end
+
+# Add the shared-library targets as a post-build pass, so the default
+# static-build pipeline remains untouched.
+MRuby.each_target do
+  next unless name == "host"
+
+  libdir = File.join(build_dir, libdir_name)
+  vermap = File.join(build_dir, "libmruby.map")
+  vertag = "MRUBY_#{MRuby::Source::MRUBY_RELEASE_NO}"
+
+  # Generate the version script eagerly — it has no .o dependencies and is
+  # tiny enough that lazy generation isn't worth the rake plumbing.
+  mkdir_p File.dirname(vermap)
+  File.write(vermap, <<~MAP)
+    #{vertag} {
+      global: *;
+      local:  *;
+    };
+  MAP
+
+  major = MRuby::Source::MRUBY_RELEASE_MAJOR
+  minor = MRuby::Source::MRUBY_RELEASE_MINOR
+
+  [
+    [libmruby_static,      "libmruby"],
+    [libmruby_core_static, "libmruby_core"],
+  ].each do |archive, basename|
+    so      = File.join(libdir, "#{basename}.so")
+    symlink = "#{so}.#{major}.#{minor}"
+    soname  = "#{basename}.so.#{major}.#{minor}"
+
+    # Build .so from the static archive via --whole-archive.
+    file so => [archive, vermap] do |t|
+      _pp "LD", so.relative_path
+      sh "#{cc.command} -shared -fPIC -o #{so}" \
+         " -Wl,-soname,#{soname}" \
+         " -Wl,--version-script=#{vermap}" \
+         " -Wl,--whole-archive #{archive} -Wl,--no-whole-archive" \
+         " -lm"
+    end
+    products << so
+
+    # SONAME-matching symlink: needed so executables linked with -lmruby
+    # (which embeds the SONAME as DT_NEEDED) can find the library at
+    # runtime via standard search paths.
+    file symlink => so do |t|
+      _pp "LN", "#{symlink.relative_path} -> #{File.basename(so)}"
+      rm_f symlink
+      File.symlink(File.basename(so), symlink)
+    end
+    products << symlink
+  end
+end