diff --git a/README.txt b/README.txt
index c5bae96b9c..e62d319c07 100644
--- a/README.txt
+++ b/README.txt
@@ -8,6 +8,7 @@ implementation. It is not an introduction to the language itself.
 
 - Platform support
 - Compiling the Factor VM
+- Libraries needed for compilation
 - Bootstrapping the Factor image
 - Running Factor on Unix with X11
 - Running Factor on Mac OS X - Cocoa UI
@@ -59,6 +60,17 @@ for your platform.
 Compilation will yield an executable named 'factor' on Unix,
 'factor-nt.exe' on Windows XP/Vista, and 'factor-ce.exe' on Windows CE.
 
+* Libraries needed for compilation
+
+For X11 support, you need recent development libraries for libc, Freetype,
+X11, OpenGL and GLUT. On a Debian-derived Linux distribution (like Ubuntu),
+you can use the line
+
+sudo apt-get install libc6-dev libfreetype6-dev libx11-dev glutg3-dev
+
+to grab everything (if you're on a non-debian-derived distro please tell us
+what the equivalent command is on there and it can be added :)
+
 * Bootstrapping the Factor image
 
 The boot images are no longer included with the Factor distribution