--- /dev/null
+
+<p>
+ I/O plugins provide an way to do pre- and post-processing outside the normal
+ session. Pre-plugins run before Ardour does any processing, post-plugins run
+ after Ardour has done all processing. The rationale is to provide a relatively
+ lightweight pre-/post-processing workflow as compared to using busses.
+</p>
+
+<p>
+ A common use case is wet recording where a number of plugins are applied
+ directly to the physical input. The processed signal then can be routed to any
+ number of tracks or busses in Ardour. This is a lot like doing some of the
+ processing with a chain of guitar pedals, then feeding the signal to an Aux In
+ port on a mixing console or an input port on a multi-effects digital
+ pedalboard.
+</p>
+
+<h2>Adding I/O plugins</h2>
+
+<p>
+ New I/O plugins can be added in the <kbd class="title">I/O Plugins</kbd>
+ dialog (<kbd class="menu">Window > I/O Plugins</kbd>).
+</p>
+
+<figure>
+ <img style="width:50%;" width="50%" src="/images/io-plugins-empty-slots.png" alt="Empty slots in the I/O Plugins dialog">
+ <figcaption>Empty slots in the I/O Plugins dialog</figcaption>
+</figure>
+
+<p>
+ Right-clicking opens the same menu for plugin selection available for mixer
+ channel strips:
+</p>
+
+<figure>
+ <img style="width:50%;" width="50%" src="/images/io-plugins-right-click-menu.png" alt="Right-click menu in the I/O Plugins dialog">
+ <figcaption>Right-click menu in the I/O Plugins dialog</figcaption>
+</figure>
+
+<p>
+ Double-clicking opens the <kbd class="title">Plugin Selector</kbd> dialog.
+</p>
+
+<p>
+ Once a plugin has been selected and added, it shows in either Pre- or
+ Post-process section depending on your choice.
+</p>
+
+<figure>
+ <img style="width:50%;" width="50%" src="/images/io-plugins-one-plugin-added.png" alt="ACE Compressor added to the pre- section">
+ <figcaption>ACE Compressor added to the Pre-process section</figcaption>
+</figure>
+
+<h2>Routing I/O plugins</h2>
+
+<p>
+ I/O plugins have the same user interface for setting input and outputs that is
+ also available in mixer channel strips. The button above the plugin name opens
+ a drop-down menu for quickly choosing an input port. The button below opens
+ the drop-down menu for choosing the output port.
+</p>
+
+<figure>
+ <img style="width:50%;" width="50%" src="/images/io-plugins-choose-output.png" alt="Choosing output for an I/O plugin">
+ <figcaption>Choosing output for an I/O plugin</figcaption>
+</figure>
+
+<p>
+ Additionally, new tracks automatically connected to an I/O plugin can be
+ easily created in the <kbd class="title">Recorder</kbd> window by clicking the
+ <kbd class="key">+</kbd> button and then setting a new for that track.
+</p>
+
+<figure>
+ <img style="width:50%;" width="50%" src="/images/io-plugins-new-track-from-io-plugin.png" alt="New track connected to an I/O plugin">
+ <figcaption>New track connected to an I/O plugin</figcaption>
+</figure>