diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..3d78e13
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+README.html
+venv
diff --git a/Dockerfile b/Dockerfile
index 50f2fbf..03a41ea 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3-alpine
+FROM docker.io/library/python:3-alpine
 WORKDIR /usr/src/app
 RUN pip install --no-cache-dir websockets
 COPY unwebsockify.py ./
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..7ceb861
--- /dev/null
+++ b/README.md
@@ -0,0 +1,49 @@
+Unwebsockify is a TCP to WebSocket proxy/bridge.  It accepts a plain
+TCP connection and connects to a WebSocket server, effectively adding
+WS support to a client that does not natively support it.  It is
+essentially the opposite of
+[websockify](https://github.com/novnc/websockify).
+
+Note that this only handles simple byte streams of data, with no
+support for conveying WebSockets message framing back to the client.
+In most cases, **specifying the WebSockets subprotocol (via
+`--subproto`) is necessary**, because the server expects it to match
+some particular string.
+
+# Install dependencies
+
+Using a virtual environment:
+
+    python3 -m venv venv
+    venv/bin/pip install -r requirements.txt
+    venv/bin/python unwebsockify.py -h
+
+Or use docker (or replace `docker` with `podman`):
+
+    docker build -t unwebsockify .
+    docker run -p 13232:13232 unwebsockify -h
+
+# Usage
+
+    usage: unwebsockify.py [-h] [--port PORT] [--listen ADDR] [--subproto SUBPROTO] URL
+
+    positional arguments:
+      URL                   WebSocket URL (ws://.. or wss://..)
+
+    optional arguments:
+      -h, --help                         show this help message and exit
+      --port PORT, -p PORT               TCP listen port
+      --listen ADDR, -l ADDR             TCP listen address
+      --subproto SUBPROTO, -s SUBPROTO   WebSocket subprotocol
+
+# Example
+
+Eclipse Mosquitto supports WebSockets on the server side, but not on
+the client side (for bridging).  To bridge two MQTT instances via
+websockets, run unwebsockify on the client:
+
+    venv/bin/python unwebsockify.py --port 13232 --subproto mqtt wss://server/
+
+and configure and run the MQTT client instance with e.g.
+
+    address 127.0.0.1:13232
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..14774b4
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1 @@
+websockets