diff --git a/bin/ruby-package b/bin/ruby-package
new file mode 100755
index 00000000..e96ad0ca
--- /dev/null
+++ b/bin/ruby-package
@@ -0,0 +1,45 @@
+#!/usr/bin/env bash
+set -e
+
+definition="$1"
+if [ -z "$definition" ]; then
+  echo "usage: ruby-package DEFINITION"
+fi
+
+package="${definition##*/}"
+prefix="/tmp/ruby-build/-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------/$package"
+
+
+# ruby-build "$definition" "$prefix"
+cwd="$(pwd)"
+cd "${prefix}/.."
+
+# FIXME don't assume share is in cwd
+mkdir -p "${package}.rubypackage/bin"
+cp "${cwd}/share/ruby-package/"* "${package}.rubypackage/bin"
+
+mkdir -p "${package}.rubypackage/metadata"
+echo -n "$prefix" > "${package}.rubypackage/metadata/prefix"
+echo -n "$package" > "${package}.rubypackage/metadata/package"
+
+cd "$package"
+
+while read line; do
+  binary="${line#Binary file }"
+  if [ "$line" = "$binary" ]; then
+    # plain text match
+    text="${line%%:*}"
+    echo "$text" >> "../${package}.rubypackage/metadata/text-files"
+  else
+    # binary match
+    binary="${binary% matches}"
+    echo "$binary" >> "../${package}.rubypackage/metadata/binary-files"
+  fi
+done < <( grep -m 1 -R "$prefix" * )
+
+tar cf "../${package}.rubypackage/package.tar" *
+
+cd ..
+
+tar czf "${cwd}/${package}.rubypackage.tar.gz" "${package}.rubypackage"
+rm -fr "${package}.rubypackage"
diff --git a/share/ruby-package/ruby-package-install b/share/ruby-package/ruby-package-install
new file mode 100755
index 00000000..6be5b6f8
--- /dev/null
+++ b/share/ruby-package/ruby-package-install
@@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+set -e
+
+prefix="$1"
+if [ -z "$prefix" ]; then
+  echo "usage: ruby-package-install PREFIX" >&2
+  exit 1
+fi
+
+resolve_link() {
+  $(type -p greadlink readlink | head -1) $1
+}
+
+abs_dirname() {
+  local cwd="$(pwd)"
+  local path="$1"
+
+  while [ -n "$path" ]; do
+    cd "${path%/*}"
+    local name="${path##*/}"
+    path="$(resolve_link "$name" || true)"
+  done
+
+  pwd
+  cd "$cwd"
+}
+
+bin_root="$(abs_dirname "$0")"
+package_root="${bin_root}/.."
+package_prefix="$(cat "${package_root}/metadata/prefix")"
+package="$(cat "${package_root}/metadata/package")"
+
+mkdir -p "$prefix"
+cd "$prefix"
+prefix="$(pwd)"
+
+rewrite() {
+  kind="$1"
+  while read file; do
+    path="${prefix}/$file"
+    cp "$path" "${path}.orig"
+    "${bin_root}/ruby-package-rewrite-$kind" "$package_prefix" "$prefix" < "${path}.orig" > "$path"
+    rm "${path}.orig"
+  done < "${package_root}/metadata/${kind}-files"
+}
+
+tar xzf "${package_root}/package.tar"
+rewrite binary
+rewrite text
diff --git a/share/ruby-package/ruby-package-rewrite-binary b/share/ruby-package/ruby-package-rewrite-binary
new file mode 100755
index 00000000..debd559f
--- /dev/null
+++ b/share/ruby-package/ruby-package-rewrite-binary
@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+set -e
+
+src_prefix="$1"
+dst_prefix="$2"
+
+if [ -z "$src_prefix" ] || [ -z "$dst_prefix" ]; then
+  echo "usage: ruby-package-install-binary SRC_PREFIX DST_PREFIX" >&2
+  exit 1
+fi
+
+hexify() {
+  xxd -c 1 -p | sed 's/^00$/,/' | tr ',\n' '\n '
+}
+
+search_hex="$(echo -n "$src_prefix" | hexify)"
+replace_hex="$(echo -n "$dst_prefix" | hexify)"
+
+hexify |
+awk '
+  BEGIN {
+    search_hex=" '"$search_hex"'";
+    replace_hex=" '"$replace_hex"'";
+    split(search_hex, search);
+    split(replace_hex, replace);
+    search_len=length(search);
+    replace_len=length(replace);
+  }
+  { matched=0 }
+  / '"$search_hex"'/ {
+    result=replace_hex substr($0, length(search_hex) + 1);
+    for (i=length(replace)+1; i<=length(search); i++)
+      result=result "00 ";
+    print result;
+    matched=1
+  }
+  { if (matched == 0) print $0 }
+' |
+sed 's/$/00/' |
+xxd -p -r
diff --git a/share/ruby-package/ruby-package-rewrite-text b/share/ruby-package/ruby-package-rewrite-text
new file mode 100755
index 00000000..8d9d87bf
--- /dev/null
+++ b/share/ruby-package/ruby-package-rewrite-text
@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+set -e
+
+src_prefix="$1"
+dst_prefix="$2"
+
+if [ -z "$src_prefix" ] || [ -z "$dst_prefix" ]; then
+  echo "usage: ruby-package-install-text SRC_PREFIX DST_PREFIX" >&2
+  exit 1
+fi
+
+sed "s:${src_prefix}:${dst_prefix}:g"