Free Computer Science books

One of the best things about the Computer Science field is that many of the authors are big supporters of the idea of Open Education, as a consequence have lots of sites like these that provide free computer books:

• http://www.freetechbooks.com/
  
• http://freecomputerbooks.com/compscCategory.html
  
• http://www.coderholic.com/25-free-computer-science-books/
  
• http://www.sciencebooksonline.info/computer-science.html
  
• http://www.freebookcentre.net/CompuScience/compscCategory.html
  
• http://www.reddit.com/r/csbooks/
  
• http://www.e-booksdirectory.com/listing.php?category=24
  
• http://greenteapress.com/
  
• http://www.techbooksforfree.com/