Added Speaking JavaScript online book from Dr. Axel Rauschmayer

free-programming-books.md

@@ -973,6 +973,7 @@
 * [Oh My JS](https://leanpub.com/ohmyjs/read) *(Leanpub, by Azat Mardanov)*
 * [O'Reilly Programming JavaScript Applications - Early Release](http://chimera.labs.oreilly.com/books/1234000000262/index.html)
 * [Patterns For Large-Scale JavaScript Application Architecture](http://addyosmani.com/largescalejavascript/) - Addy Osmani
+* [Speaking JavaScript](http://speakingjs.com/es5/) - Dr. Axel Rauschmayer 
 * [The JavaScript Tutorial](http://javascript.info/)
 * [The Problem with Native JavaScript APIs](http://chimera.labs.oreilly.com/books/1234000001655) (PDF)
 * [You Don't Know JS](https://github.com/getify/You-Dont-Know-JS)