Programming Resources

MOOC (Massive Online Open Courses)

Free Code Camp - My personal favorite. But only try this one if you are already a programmer and just want to exercise your coding muscles.
Saylor Academy - Non profit Australian Academy offering various CS courses. Highly recommended!
Open2Study - Launched in April 2013 by a collaboration of several Australian universities. The number of programming specific courses is currently small, but should grow in future considering that they are more leaning towards career-oriented than core academic courses.
MIT Open Courseware - One of the best online resource to get learning content. However, you won't get any certificates on course completion.
Stanford Online - Another great university that provisions learning content through the online channel. Again, no certificates, but still great course content.
Coursera - Comprehensive curriculum and large number of programming courses to choose from. A pity they started monetizing their students by offering paid-only certificates recently.
edX.org - ~~Non profit, open source~~ Professional and Profiteerig institute and currently ~~the most recommended~~ not recommended.

Advent of code - Lots of programming problems for you to solve! A gamification approach which is fun and enjoyable. It is said that people abuse the hell out of languages to reach the top of leaderboard here. Requires a Github, Reddit or Google account to sign in.
CodingBat - python and java - Coding puzzles and problems in python and java.
PySchools - python - Programming practice tests specific to python.
Project Euler - One of the "old-school", but interesting sites that features solving math problems through various levels. There is no code-evaluation, you just have to write your own code, come up with answers and post the answer to go to the next level.
/r/dailyprogrammer - A programming puzzle a day keeps woes and dispair away. A subreddit where programming problems are posted and peer-reviewed every day.
/r/learnpython wiki - Pointer to more python practice resources.
Code Wars - A must visit place for all programmers. The practice challenges are really addictive.
Khan Academy - video lessons - Good for learning HTML/CSS - both practice tests and video sessions.

Stack Overflow - No need to say anything there!
Unix and Linux Q/A - This is where I usually go if Google cannot help me with a linux problem.
Super User - Though not specific to programming, but very useful nevertheless.
Code Project - If you are into Microsoft Technologies like ASP.NET/C#, this site is for you.

Reddit Programming Help - A must-visit place for every programmer. You will definitely gain something from this site, whether its learning, tips, guidance or just the satisfaction of helping a fellow developer.
Dictionary of Algorithms and Data Structure - Visit this site if you run out of ideas for program creation. Almost every algorithm invented by mankind could be found here (Except the patented ones of course!).
Design Patterns Catalog - A collection of software design patterns and processes to follow, written by Martin Fowler, one of the best minds in the industry.
Great Github list of public datasets - A great source of published data in case you are developing an app.
UPC Database - The canonical place on web to lookup barcode items. An invaluable resource if you are developing a Barcode app.

Octokit client libraries - Octokit library is used to access the github API. This comes in multiple flavors and languages including .NET, Ruby and Java.