在stackoverflow找到了不错的东东，特此记录。源地址：

Meta-List

•  (List of Free Books)
•  (Free Online books)
•  (Free Downloadable German Books)

Graphics Programming

• Nvidia 
• Nvidia 
• Nvidia 
• Wolfgang Engel 

Language Agnostic:

•  by Karl Seguin
•  (Lectures by Donald Knuth)
•  (Introduction to Open Source Software)
•  (Courtesy )
•  - Class Lectures and Slides
•  - MIT Press
•  - IEEE Computer Society Press
•  - MIT
•  (Draft Copy)
•  - Cambridge University Press. 2008.
•  - Springer, 2010
•  - Addison-Wesley, 1991

ASP.NET MVC:

Assembly Language:

Bash

C/C++

•  (Open Publication License) ()

C#

• See .NET below

Django

Erlang

F#

Forth

Git

Grails - 

Haskell

HTML

Java

•  (CreativeCommons Attribution Non-commercial Share Alike License)

JavaScript

•  (starts with JavaScript basics)
•  (Mozilla Developer Network)

Linux

Lisp

Lua

•  (for v5 but still largely relevant)
•  not entirely free, but has a lot of free chapters and accompanying code.

Maven

Mercurial

.NET (C#)

•  Covers C#1.0 and 2.0 (Courtesy of )
•  (VS 2003-2005 only)
•  (514 pages)
•  (Intro to programming)
•  (Download) (.ZIP) [dead link]
•  (Free Ebook courtesy of ) [dead link]

NoSQL

Objective-C

Oracle Server

• Oracle 

Oracle PL/SQL

Parrot / Perl 6

•  (Work in progress)

Perl

•  Meta-List
•  (Open Publication License)

PHP

•  (Wiki that contains O'Reilly's PHP In a Nutshell)

PowerShell

Prolog

PostgreSQL

Python

•  Meta-List

Ruby

•  ( via )

Scala

•  (Github)
•  (Github)
•  (published earlier as "The Definitive Guide to Lift", )

Scheme

Smalltalk

•  Courtesy of Stéphane Ducasse
•  (Smalltalk IDE)

Subversion

SQL (Implementation agnostic)

• ,Richard T. Snodgrass
•  - A guide to SQL database performance for developers

Vim