Thanks for everyone submitting more books that I wasn’t aware of. I’ll be updating the list shortly - Tim.
How to Be a Programmer
http://samizdat.mines.edu/howto/HowToBeAProgrammer.html
How to Design Programs
http://www.htdp.org/2002-09-22/Book/
Practical Theory of Programming
http://www.cs.toronto.edu/~hehner/aPToP/
Software Engineering for Internet Applications
http://philip.greenspun.com/seia/
Structure and interpretation of computer programs
http://mitpress.mit.edu/SICP/
More programming books http://2020ok.com/3839.htm
The Programmers Stone
http://www.reciprocality.org/Reciprocality/r0/
Subversion Version Control: Using the Subversion Version Control System in Development Projects
http://www.phptr.com/promotions/promotion….84&redir=1&rl=1
Ada
Ada 95 Rational
http://www.adaic.org/standards/95rat/RATht…5-contents.html
Ada 95 Reference Manual
http://www.adahome.com/rm95/
Changes to Ada 1987 - 1995
http://www.oopweb.com/Ada/Documents/Change…lumeFrames.html
Ada 95: The Lovelace Tutorial
http://www.adahome.com/Tutorials/Lovelace/master.htm
The Big Online Book of Linux Ada Programming
http://www.pegasoft.ca/resources/boblap/book.html
Algorithms
Algorithms and Complexity
http://www.cis.upenn.edu/~wilf/AlgComp.html
Programming Algorithms http://2020ok.com/3870.htm
Information Theory, Inference, and Learning Algorithms
http://www.inference.phy.cam.ac.uk/mackay/itprnn/book.html
Assembly
Assembly Language Tutorial
http://www.oopweb.com/Assembly/Documents/a…lumeFrames.html
Programming From the Ground Up
http://download.savannah.gnu.org/releases/pgubook/
Assembly Language Programming http://2020ok.com/3954.htm
Ralph Brown's Interrupt List
http://www.oopweb.com/Assembly/Documents/I…lumeFrames.html
The Art of Assembly Language Programming
http://www.oopweb.com/Assembly/Documents/A…lumeFrames.html
The Assembly Language Database
http://www.oopweb.com/Assembly/Download/NortonGuide.zip
Win32 Programming for x86 Assembly Language Programmers
http://www.oopweb.com/Assembly/Documents/W…lumeFrames.html
C
A Tutorial on Pointers and Arrays in C
http://www.oopweb.com/CPP/Documents/CPoint…lumeFrames.html
C Programming
http://www.oopweb.com/CPP/Documents/CProgr…lumeFrames.html
Object Orientated Programming in ANSI-C
http://www.planetpdf.com/developer/article…?contentid=6635
The C Book
http://publications.gbdirect.co.uk/c_book/
Writing Bug-Free C Code
http://www.duckware.com/bugfreec/index.html
C - Elements of Style
http://www.computer-books.us/c_3.php
Learning GNU C
http://www.linuxtopia.org/online_books/pro…nu_c/index.html
C++
An Overview Of The C++ Programming Langauge
http://www.oopweb.com/CPP/Download/crc.zip
C++ Annotations
http://www.oopweb.com/CPP/Documents/CPPAnn…lumeFrames.html
C++ Annotations
http://www.oopweb.com/CPP/Download/cplusplus.zip
C++ Coding Standard
http://www.oopweb.com/CPP/Documents/CodeSt…lumeFrames.html
C & C++ http://2020ok.com/3956.htm
C++ Course
http://www.oopweb.com/CPP/Download/CPPCourse.zip
C++ How To
http://www.oopweb.com/CPP/Documents/CPPHOW…lumeFrames.html
C++ In Action
http://www.relisoft.com/book/index.htm
C++: A Dialog
http://www.steveheller.com/cppad/cppad.htm
How To Think Like A Computer Scientist with C++
http://www.oopweb.com/CPP/Documents/ThinkC…lumeFrames.html
Introduction To OOP Using C++
http://www.oopweb.com/CPP/Documents/Intro2…lumeFrames.html
Introduction To OOP Using C++
http://www.oopweb.com/CPP/Download/Intro2OOP.zip
Objects First
http://www.oopweb.com/CPP/Documents/Object…lumeFrames.html
Optimizing C++
http://www.steveheller.com/opt/
STL Guide
http://www.oopweb.com/CPP/Documents/STLGui…lumeFrames.html
STL Guide
http://www.oopweb.com/CPP/Download/stl.zip
The Function Pointer Tutorials
http://www.oopweb.com/CPP/Documents/Functi…lumeFrames.html
The Standard Template Library Tutorial
http://www.oopweb.com/CPP/Documents/STL/VolumeFrames.html
Thinking in C++
http://www.planetpdf.com/developer/article…?ContentID=6634
Thinking in C++, Second Edition (Volumes 1 & 2)
http://mindview.net/Books/TICPP/ThinkingInCPP2e.html
An Introduction to C++ Programming
http://www.computer-books.us/cpp_1.php
Programming in C++ - Rules and Recommendations
http://www.computer-books.us/cpp_6.php
A Beginners C++ Book
http://www.uow.edu.au/~nabg/ABC/ABC.html
C++ GUI Programming with Qt 3
http://www.phptr.com/promotion/1484?redir=1
Cross-Platform GUI Programming with wxWidgets
http://www.phptr.com/promotion/1484?redir=1
C#
C# in Detail
http://www.computer-books.us/csharp_0005.php
C# - The Basics
http://www.computer-books.us/csharp_0004.php
C# Language Specification
http://www.computer-books.us/csharp_1.php
Data Structures and Algorithms with Object-Oriented Design Patterns in C#
http://www.computer-books.us/csharp_2.php
C# Programming http://2020ok.com/697342.htm
Dissecting a C# Application - Inside SharpDevelop
http://www.computer-books.us/csharp_3.php
C# tutorial (2 .pdf's)
http://www.ssw.uni-linz.ac.at/Teaching/Lec…Sharp/Tutorial/
CGI
CGI Programming on the World Wide Web
http://www.oreilly.com/openbook/cgi/
CGI Programming http://2020ok.com/4025.htm
COBOL
zingCOBOL - A Beginners Guide to COBOL Programming
http://www.computer-books.us/cobol_0006.php
Teach Yourself COBOL in 21 Days
http://www.computer-books.us/cobol_0005.php
WebSphere Studio COBOL for Windows - Language Reference
http://www.computer-books.us/cobol_1.php
COBOL Programming Course
http://www.computer-books.us/cobol_2.php
COBOL Programming http://2020ok.com/3969.htm
WebSphere Studio COBOL for Windows - Programming Guide
http://www.computer-books.us/cobol_3.php
HP COBOL II/XL Reference Manual
http://www.computer-books.us/cobol_4.php
Databases
MySQL Reference Manual
http://dev.mysql.com/doc/
Database http://2020ok.com/549646.htm
Oracle 10g Database Book and Documentation Library
http://wtcis.wtamu.edu/oracle/
Delphi/Pascal
Delphi 2005 Tutorial for Beginners
http://www.xcalibur.co.uk/training/Delphi2005/index.php
Delphi Training
http://www.xcalibur.co.uk/training/delphi/oldindex.html
Essential Delphi
http://marcocantu.com/edelphi/default.htm
Essential Pascal
http://marcocantu.com/epascal/default.htm
Delphi Language Guide - Delphi For The Microsoft .NET Framework
http://www.computer-books.us/delphi_2.php
Delphi Database Application Developers Guide
http://www.computer-books.us/delphi_1.php
Fortran
Numerical Recipes with Fortran 77
http://www.library.cornell.edu/nr/cbookfpdf.html
Numerical Recipes with Fortran 90
http://www.library.cornell.edu/nr/cbookf90pdf.html
Professional Programmer's Guide to Fortran 77
http://www.computer-books.us/fortran_3.php
User Notes on Fortran Programming (UNFP)
http://www.ibiblio.org/pub/languages/fortran/
HTML
HTML 4.01 Specifications
http://www.oopweb.com/HTML/Documents/HTML4/VolumeFrames.html
Web Development http://2020ok.com/3510.htm
Writing HTML
http://www.oopweb.com/HTML/Documents/Writi…lumeFrames.html
Java
How to Think Like a Computer Scientist with Java
http://www.oopweb.com/Java/Documents/Think…lumeFrames.html
Introduction to Programming Using Java
http://www.oopweb.com/Java/Documents/Intro…lumeFrames.html
Introduction To Programming Using Java
http://www.linuxtopia.org/online_books/pro…ming/index.html
Java Programming Tutorial: Introduction to Computer Science
http://www.oopweb.com/Java/Documents/JavaN…lumeFrames.html
Thinking in Java, 3rd Edition
http://www.mindview.net/Books/TIJ/
Thinking in Enterprise Java
http://www.ibiblio.org/pub/docs/books/eckel/
More Java Books http://kickjava.com/freeBooks.html
Java AWT Reference
http://www.oreilly.com/catalog/javawt/book/index.html
Enterprise JavaBeans
http://www.computer-books.us/java_1.php
Essentials of the Java Programming Language - Part 1
http://www.computer-books.us/java_2.php
Essentials of the Java Programming Language - Part 2
http://www.computer-books.us/java_3.php
Exploring Java
http://www.computer-books.us/java_4.php
Introduction to Computer Science using Java
http://www.computer-books.us/java_5.php
Java Development http://2020ok.com/3608.htm
Java Language Reference
http://www.computer-books.us/java_8.php
Java Servlet Programming
http://www.computer-books.us/java_9.php
Java Web Services Tutorial
http://www.computer-books.us/java_10.php
Java Look and Feel Design Guidelines, Second Edition
http://java.sun.com/products/jlf/ed2/book/index.html
The Design Patterns: Java Companion
http://www.patterndepot.com/put/8/JavaPatterns.htm
1000 Java Tips e-Book
http://javaa.com/
Apache Jakarta Commons: Reusable Java™ Components
http://www.phptr.com/promotion/1484?redir=1
Java™ Application Development on Linux®
http://www.phptr.com/promotion/1484?redir=1
Practical Artificial Intelligence Programming in Java
http://www.markwatson.com/opencontent/javaai_lic.htm
Javascript
Voodoo's Introduction to Javascript
http://www.oopweb.com/JavaScript/Documents…lumeFrames.html
Javascript Programming http://2020ok.com/3617.htm
Linux
Linux Device Drivers, Third Edition
http://lwn.net/Kernel/LDD3/
The Linux Development Platform
http://www.phptr.com/promotion/1484?redir=1
Understanding the Linux Virtual Memory Manager
http://www.phptr.com/promotion/1484?redir=1
Self-Service Linux®: Mastering the Art of Problem Determination
http://www.phptr.com/promotion/1484?redir=1
Linux® Quick Fix Notebook
http://www.phptr.com/promotion/1484?redir=1
Managing Linux Systems with Webmin: System Administration and Module Development
http://www.phptr.com/promotion/1484?redir=1
An Introduction to GCC
http://www.linuxtopia.org/online_books/an_…_gcc/index.html
Linux http://2020ok.com/3756.htm
Using the GNU Compiler Collection (GCC)
http://www.linuxtopia.org/online_books/pro…tion/index.html
Bash Reference Guide
http://www.linuxtopia.org/online_books/bas…uide/index.html
Bash Guide for Beginners
http://www.linuxtopia.org/online_books/bas…ners/index.html
Advanced Bash Scripting Guide
http://www.linuxtopia.org/online_books/adv…uide/index.html
Linux Kernel Module Programming Guide
http://www.linuxtopia.org/online_books/Lin…uide/index.html
Red Hat Linux Developer Tools Guide
http://www.linuxtopia.org/online_books/red…uide/index.html
Linux Debugging with gdb Guide
http://www.linuxtopia.org/online_books/red…_gdb/index.html
Using cpp, the C Preprocessor Guide
http://www.linuxtopia.org/online_books/pro…ssor/index.html
Lisp
Loving Lisp - the Savy Programmer's Secret Weapon
http://www.markwatson.com/opencontent/lisp_lic.htm
List Programming http://2020ok.com/3981.htm
Open Source
Rapid Application Development with Mozilla
http://www.phptr.com/promotion/1484?redir=1
Creating Applications with Mozilla
http://books.mozdev.org/chapters/index.html
Free as in Freedom
http://www.oreilly.com/openbook/freedom/index.html
Managing Projects with GNU make, 3rd Edition
http://www.oreilly.com/catalog/make3/book/index.csp
OpenSources: Voices from the Open Source Revolution
http://www.oreilly.com/catalog/opensources/book/toc.html
Understanding Open Source and Free Software Licensing
http://www.oreilly.com/catalog/osfreesoft/book/
Embedded Software Development with eCos
http://www.phptr.com/promotion/1484?redir=1
Open Source Security Tools: A Practical Guide to Security Applications
http://www.phptr.com/promotion/1484?redir=1
Perl
HTMLified Perl 5 Reference Guide
http://www.oopweb.com/Perl/Documents/Perl5…lumeFrames.html
Perl 5 Documentation
http://www.oopweb.com/Perl/Documents/PerlD…lumeFrames.html
Perl for Perl Newbies
http://www.oopweb.com/Perl/Documents/P4PNe…lumeFrames.html
Perl for Win32 FAQ
http://www.oopweb.com/Perl/Documents/PerlW…lumeFrames.html
Picking Up Perl
http://www.oopweb.com/Perl/Documents/Picki…lumeFrames.html
Picking Up Perl
http://www.linuxtopia.org/online_books/perl/index.html
Perl Programming
http://www.2020ok.com/4045.htm
Practical Perl Programming
http://www.oopweb.com/Perl/Documents/ppp/VolumeFrames.html
Beginning Perl
http://www.perl.org/books/beginning-perl/
Impatient Perl
http://www.perl.org/books/impatient-perl/
Extreme Perl
http://www.extremeperl.org/bk/home
MacPerl: Power & Ease
http://macperl.com/ptf_book/r/MP/i2.html
Embedding Perl in HTML with Mason
http://www.masonbook.com/
Perl for the Web
http://www.globalspin.com/thebook/
Practical mod_perl (1st edition)
http://modperlbook.com/
Web Client Programming with Perl
http://www.oreilly.com/openbook/webclient/
Perl 5 By Example
http://www.computer-books.us/perl_0010.php
An Introduction to Perl
http://www.linuxtopia.org/Perl_Tutorial/index.html
PHP
Practical PHP Programming
http://www.hudzilla.org/phpbook/
A Programmer's Introduction to PHP 4.0 -http://www.apress.com/free/
PHP 5 Power Programming
http://www.computer-books.us/php_2.php
PHP Programming http://2020ok.com/295223.htm
Practical PHP Programming
http://www.computer-books.us/php_3.php
Prolog
Adventure in Prolog
http://www.amzi.com/AdventureInProlog/
Building Expert Systems in Prolog -http://www.amzi.com/ExpertSystemsInProlog/
Prolog programming http://2020ok.com/295223.htm
Prolog Programming A First Course
http://computing.unn.ac.uk/staff/cgpb4/prologbook/
Python
Non-Programmers Tutorial for Python
http://rupert.honors.montana.edu/~jjc/easy…ut/easytut.html
Official Python Documentation
http://www.python.org/doc/current/
Text Processing in Python -http://gnosis.cx/TPiP/
Python Reference Manual
http://docs.python.org/ref/ref.html
Python Imaging Library Handbook -http://www.pythonware.com/library/the-python-imaging-library.htm
How to Think Like a Computer Scientist - Learning with Python
http://www.greenteapress.com/thinkpython
Dive Into Python -http://diveintopython.org/
Python Programming http://2020ok.com/285856.htm
Thinking in Python
http://mindview.net/Books/TIPython
A Byte of Python
http://www.ibiblio.org/g2swap/byteofpython/read/
Ruby
Programming Ruby - The Pragmatic Programmer's Guide (First Edition)
http://www.ruby-doc.org/docs/ProgrammingRuby/
Why's (Poignant) Guide to Ruby
http://poignantguide.net/ruby/ <–the funniest programming book I have ever seen!
Samba
Samba-3 by Example: Practical Exercises to Successful Deployment
http://www.phptr.com/promotion/1484?redir=1
Samba-3 by Example: Practical Exercises to Successful Deployment, 2nd Edition
http://www.phptr.com/promotion/1484?redir=1
The Official Samba-3 HOWTO and Reference Guide
http://www.phptr.com/promotion/1484?redir=1
Implementing CIFS: The Common Internet File System
http://www.phptr.com/promotion/1484?redir=1
SQL
Comparison of Different SQL Implementations
http://www.computer-books.us/sql_0004.php
SQL - A Practical Introduction
http://www.managedtime.com/freesqlbook.php3
Introduction To Structured Query Language
http://www.computer-books.us/sql_2.php
Practical PostgreSQL
http://www.opendocspublishing.com/ppbook/
UNIX
FreeBSD Handbook
http://www.freebsd.org/doc/en_US.ISO8859-1…book/index.html
Unix http://2020ok.com/3778.htm
The UNIX-HATERS Handbook
http://research.microsoft.com/~daniel/unix-haters.html
Visual Basic and VB.net
Programming VB.NET - A Guide For Experienced Programmers
http://www.apress.com/free/
Upgrading Microsoft Visual Basic 6.0 to Microsoft Visual Basic .NET
http://msdn.microsoft.com/vbrun/staythepat…s/upgradingvb6/
Visual Basic http://2020ok.com/3996.htm
Introducing Visual Basic 2005 for Developers
http://msdn.microsoft.com/vbrun/staythepat…05/default.aspx
XML
OpenOffice.org XML Essentials
http://books.evc-cit.info/
Misc. stuff that is worth reading
FREE Trade Magazine Subscriptions & Technical Document Downloads http://i.nl03.net/ltr0/?_m=01.009i.nv.mfm.nv
The Future does not compute
http://www.praxagora.com/stevet/fdnc/toc.html
The Cathedral and the Bazaar
http://www.catb.org/~esr/writings/cathedral-bazaar/