Many people complain that reading an e-book on the laptop screen is just not possible. But, as a real programmer myself, I know how important it is to have e-books open in PDF readers as references while I code. Here is a list of 30 amazing and free e-books which can aid you in your daily programming needs in different avenues.

Lisp/Scheme:
How to Desing Programs
Let Over Lambda
On Lisp
Practical Common Lisp
Programming in Emacs Lisp
Structure and Interpretation of Computer Programs
Teach Yourself Scheme in Fixnum Days

Ruby:
Data Structures and Algorithms with Object-Oriented Design Patterns in Ruby
Learn to Program
MacRuby: The Definitive Guide
Programming Ruby
Ruby Best Practices

Javascript:
Building iPhone Apps with HTML, CSS, and JavaScript
Eloquent Javascript
jQuery Fundamentals

Haskell:
Learn You a Haskell for Great Good
Real World Haskell

Erlang:
Concurrent Programming in Erlang
Learn You Some Erlang for Great Good

Python:
Dive into Python
How to Think Like a Computer Scientist – Learning with Python

Smalltalk:
Squeak by Example
Dynamic Web Development with Seaside

Misc:
Algorithms
The Art of Assembly Language
Beginning Perl
The C Book
Compiler Construction
Learn Prolog Now!
Objective-C 2.0 Essentials

Thank you Planet Clojure (Citizen 428) 🙂