diff --git a/free-programming-books.md b/free-programming-books.md
index d7f4b2714a5fe428213a5e894f8e57e0f936246d..cd0c30d08328580a62746500c7281ae336dc1a96 100644
--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -31,6 +31,7 @@
 * [Haskell](#haskell)
 * [HTML / CSS](#html--css)
 * [Icon](#icon)
+* [IDL](#idl)
 * [Java](#java)
 * [JavaScript](#javascript)
     * [Node.js](#nodejs)
@@ -411,6 +412,12 @@
 * [The Implementation of the Icon Programming Language](http://www.cs.arizona.edu/icon/ibsale.htm)
 
 
+###IDL
+
+* [Getting Started with IDL](http://www.astro.virginia.edu/class/oconnell/astr511/IDLresources/getting-started-IDL-v7.0.pdf)
+* [Guide to Using IDL for Astronomers](http://www.astro.virginia.edu/class/oconnell/astr511/IDLresources/IDLguide.html)
+
+
 ###Java
 
 * [Artificial Intelligence - Foundation of Computational Agents](http://artint.info/html/ArtInt.html)