diff --git a/README.md b/README.md
index 46953acc..1298463c 100644
--- a/README.md
+++ b/README.md
@@ -517,7 +517,7 @@ and it will begin playing as though you'd just turned on the console.
 
 To add a new game to your library,
 choose "Load ROM File ..." from the Library menu.
-A file-picker dialog will appear,
+A [filesystem browser](#the-filesystem-browser) will appear,
 allowing you to pick any ROM image for any supported system,
 with any of the most common file extensions.
 It also allows loading ROM images from `.zip` archives,
@@ -1164,6 +1164,68 @@ icarus will make a reasonable guess.
 This is enough to get the game running,
 but does not necessarily reflect the original cartridge.
 
+The Filesystem Browser
+----------------------
+
+Sometimes higan will need
+to ask you to choose a file or folder.
+For this, it uses a special Filesystem Browser dialog.
+Although many operating systems provide a native filesystem browser,
+they do not all allow the same customizations.
+Therefore,
+higan provides its own filesystem browser
+that works the same way on every platform.
+
+The filesystem browser shows the contents of some particular folder,
+and allows you to select one of those items.
+
+Across the top of the window,
+a text-box displays the path of the current folder.
+If you want to browse a specific path,
+you may edit the contents of this box
+and press Enter to switch to the new location.
+
+The button with two blue arrows at the top-right is "Refresh".
+Pressing this button will check for
+added (or removed) items in the current folder,
+and add (or remove) them to (or from) the list.
+
+The button with the house at the top-right is "Home".
+Pressing this button will switch to your home folder.
+
+The button with the green up-arrow at the top right is "Parent".
+Pressing this button will
+switch to the parent of the current folder.
+
+Most of the filesystem browser lists the contents
+of the current directory.
+Double-clicking a folder,
+or selecting it and pressing Enter,
+will switch to showing the contents of that directory.
+If the list has keyboard focus,
+typing any text will jump to the first inem in the list
+whose name begins with the text you typed.
+
+If a drop-down list appears in the bottom-left,
+it allows you to choose which files appear in the list,
+based on file-extension.
+
+If this filesystem browser is asking for a file,
+you can choose one
+by double-clicking it,
+by selecting it and pressing Enter,
+or by selecting it and clicking the "Select" button in the bottom-right.
+
+If this filesystem browser is asking for a directory,
+you can choose one
+by selecting it and clicking the "Select" button in the bottom-right.
+Double-clicking
+or selecting and pressing Enter don't work,
+they just switch to viewing that directory.
+
+The "Cancel" button in the bottom-right
+closes the file-system browser without selecting anything.
+
 The Game Library
 ================