diff --git a/README.md b/README.md
new file mode 100644
index 0000000..fea373b
--- /dev/null
+++ b/README.md
@@ -0,0 +1,32 @@
+# musicxmldiff
+
+musicxmldiff is "diff" for [MusicXML](https://www.musicxml.com/).
+
+![Demo](https://github.com/labocho/musicxmldiff/blob/master/demo.png?raw=true)
+
+# How to use
+
+1. Open https://musicxmldiff.penguinlab.jp/
+2. Select two MusicXML files to compare
+3. Select part
+
+
+# Limitation
+
+This version is "beta".
+
+* Don't support `<score-timewise>` data.
+* Don't support compressed data (.mxl).
+* May not display some objects over multiple measures (eg. cresc. or slurs)
+* Web app only (No desktop app).
+
+
+# Development
+
+    yarn install
+    yarn start
+
+# License
+
+See `LICENSE`
+
diff --git a/TODO.md b/TODO.md
deleted file mode 100644
index d183e83..0000000
--- a/TODO.md
+++ /dev/null
@@ -1,9 +0,0 @@
-- [x] ファイルをメモリに読み込む
-- [x] XML をパース
-- [x] 小節ごと digest 生成
-- [x] digest の diff をとる
-- [x] 小節の diff をとる
-- [x] 要素のフィルタ
-- [x] 調号・音部記号・拍子記号の引き継ぎ
-- [ ] パート選択
-- [ ] CSS 導入
diff --git a/src/App.vue b/src/App.vue
index 50e88ab..06ceba7 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -18,6 +18,9 @@
     </div>
   </nav>
   <div class="container mt-4">
+    <div class="mb-4">
+      <b class="text-danger">This version is "beta". Please see <a href="/labocho/musicxmldiff/blob/master/README.md" target="_blank">limitation.</a></b>
+    </div>
     <div>
       <h4 class="mb-4">Select MusicXML files to compare</h4>
       <section class="d-flex">