• 1.  Free online book on Applied Cryptography
• 2.  Bartleby.com
• 3.  Informit Safari Tech Books Online
• 4.  The Online Books Directory
• 5.   Free online books

• 6.  IBM Online Redbooks index
• 7.  Linux Device Drivers, 2nd Edition
• 8.  MathWeb Books
• 9.  GNU Autoconf, Automake and Libtool - An Online Book