diff --git a/README.md b/README.md
index 0c9d814..9c1a8bc 100644
--- a/README.md
+++ b/README.md
@@ -26,7 +26,7 @@ The tl;dr version and golden rules of the sections in the document:
 * [Everyone is allowed to submit changes which are not just limited to code by opening merge requests](CONTRIBUTING.md#pull-requests-bugfixes-new-features-or-other-code-contributions)
 * [Documentation improvements can and even should be contributed by non developers](CONTRIBUTING.md#pull-requests-bugfixes-new-features-or-other-code-contributions)
 
-## List of supported games
+## List of supported games (hook libraries)
 * BeatStream
     * BeatStream (bst.zip) using bsthook
     * BeatStream アニムトライヴ (bst.zip) using bsthook
@@ -69,6 +69,12 @@ The tl;dr version and golden rules of the sections in the document:
     * SOUND VOLTEX IV HEAVENLY HAVEN (sdvx-01-to-04.zip) using sdvxhook
     * SOUND VOLTEX Vivid Wave (sdvx-05.zip) using sdvxhook2
 
+## ViGEm clients: Expose BT5 APIs as XBOX game controllers
+Play your favorite non-bemani arcade games with any hardware, e.g. real cabinet hardware, that
+implements BT5 APIs.
+
+See the dedicated [readme](docs/vigem/README.md) for details.
+
 ## Supported platforms
 Our main platforms are currently Windows XP and Windows 7 which are also the target platforms on the original hardware
 of those games. However, as it gets more difficult to get and maintain hardware comptible with Windows XP, this might
diff --git a/doc/vigem/README.md b/doc/vigem/README.md
new file mode 100644
index 0000000..6df623e
--- /dev/null
+++ b/doc/vigem/README.md
@@ -0,0 +1,13 @@
+# ViGEm: Virtual Gamepad Emulation Framework
+Virtual game controller emulation library. Allows us to create in code emulated XBOX controllers.
+
+This is used to hook up BT5's various IO API libraries allowing you to use any of their
+implemtations as a game controller on Windows.
+
+References:
+* [ViGEmBus](https://github.com/ViGEm/ViGEmBus)
+* [ViGEmClient](https://github.com/ViGEm/ViGEmClient)
+
+Available ViGEm client implementations:
+* [vigem-iidxio](vigem-iidxio.md): Exposes inputs provided by the iidxio API as two XBOX gamepads
+* [vigem-sdvxio](vigem-sdvxio.md): Exposes inputs provided by the sdvxio API as one XBOX gamepad
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