Free Computer Science eBooks Online : Theory of Computation

Here is a list of online  Theory of Computation  books in various formats available for free download or online reading:

Advanced Complexity Theory
by Daniel Spielman, 2001, PDF
Algorithmic Randomness and Complexity
by R. G. Downey, D. R. Hirschfeldt, 2010, 629 pages, 4MB, PDF
Bayesian Computational Methods
by Christian P. Robert, 2010, 59 pp, 3.7MB, PDF
Cellular Automata
edited by S. Bandini, B. Chopard, M. Tomassini, 2002, 379 pp, 8.3MB, PDF
Cellular Automata
Wikibooks, 2010
Cellular Automata And Complexity: Collected Papers
by Stephen Wolfram, 1994

Cellular Automata: Simplicity Behind Complexity
edited by Alejandro Salcido, 2011, 566 pages, 31MB, PDF
Combinatorial Optimization: Exact and Approximate Algorithms
by Luca Trevisan, 2011, 139 pages, 830KB, PDF
Communication Complexity
by Domotor Palvolgyi, 2005, 39 pages, 380KB, PDF
Complexity
by Rajesh R. Parwani, 2002
Complexity Theory
by Johan Hastad, 2008, 130 pages, 0.7MB, PDF
Computability and Complexity
Wikibooks, 2010

Computability and Complexity from a Programming Perspective
by Neil D. Jones, 1997, 485 pages, 1.7MB, PDF
Computability and Randomness
by Andre Nies, 2008, 447 pages, 2.6MB, PDF
Computability Theory
by Wilfried Sieg, 2006, 125 pp, 1.9MB, PDF
Computational Complexity: A Modern Approach
by Sanjeev Arora, Boaz Barak, 2008, 489 pages, 4.4MB, PDF
Computational Modeling and Complexity Science
by Allen Downey, 2008, 97 pages, 1.4MB, PDF
Finite-state Automata in Java
by Bradley Kjell
From Complexity to Creativity
by Ben Goertzel, 1996

From Philosophy to Program Size
by G. J. Chaitin, 2003, 54 pages, PS/PDF
Handbook of Quantum Information
Quantiki, 2013, online html
Introduction to Complexity Theory
by Oded Goldreich, 1999, 375 pages, 2.3MB, PDF
Introduction to Computational Complexity
by Martin Tompa, 1991, 85 pages, 1MB, PDF
Introduction to Quantum Algorithms for Physics and Chemistry
by Man-Hong Yung, et al. 2012, 44 pp, 2MB, PDF
Introduction to Quantum Cellular Automata
by B. Aoun, M. Tarifi, 2004, 46 pages, 330KB, PDF
An Introduction to Quantum Computing using Cavity QED concepts
by Zachary Burell, 2012, 53 pp, 260KB, PDF
An Introduction to the Theory of Computation
by Eitan Gurari, 1989, 314 pages, 3.2MB, ZIP/HTML
Lecture Notes on Algorithm Analysis and Computational Complexity
by Ian Parberry, 119 pages, 1.9MB, PDF
Lecture Notes on Computational Complexity
by Luca Trevisan, 2004, 171 pages, 0.9MB, PDF

Logic for Computer Scientists
by Uli Furbach, 2010
Mathematical Foundations of Automata Theory
by Jean-Eric Pin, 2012, 310 pp, 1.9MB, PDF
Notes on Automata, Logics, Games and Algebra
by K Narayan Kumar, 2007, PDF
P, NP, and NP-Completeness: The Basics of Complexity Theory
by Oded Goldreich, 2010, 190pp, 1.9MB, PS
Physics, Topology, Logic and Computation: A Rosetta Stone
by John C. Baez, Mike Stay, 2009, 73 pages, 780KB, PDF
Quantum Computation
by John Watrous, 2006, 139 pages, 660KB, PDF
Quantum Walks: A Comprehensive Review
by Salvador E. Venegas-Andraca, 2012, 88 pp, 1.5MB, PDF
Recursion Theory
by Frank Stephan, 2009, 125 pp, 610KB, PDF
Rule-based Computation and Deduction
by Helene Kirchner, Pierre-Etienne Moreau, 2001, 100 pp, 870KB, PDF
Superconducting Qubits and Circuits
by Steven M. Girvin, 2011, 132 pp, 2.9MB, PDF
Think Complexity: Complexity Science and Computational Modeling
by Allen B. Downey, 2012, 146 pp, 1.2MB, PDF
Tree Automata Techniques and Applications
by H. Comon, M. Dauchet, R. Gilleron, 2008, 262 pages, 2MB, PDF