Based on Java, Greenfoot provides a really easy introduction into Programming and Object Orientated Programming in particular. It is open source and available for Windows, Mac and Linux.

HOW TO GET STARTED IN GREENFOOT

I have followed Episodes 1 to 27 of the Joy Of Code by Mik Kolling as the explanation and coverage of key skills is exceptional. What you will find in my posts below are summaries/revision notes produced whilst working through the episodes that I can use to support others following the series. I will not necessarily continue to work through each example but really hope that Mik continues to produce them!

Ruby is a very cool language. According to the Ruby Organization it is

A dynamic, open source programming language with a focus on simplicity and productivity. It has an elegant syntax that is natural to read and easy to write.

The following examples will give you a brief introduction into the language but for more complete documentation you will want to view the documentation section of the organization homepage.

Prolog is focused around logic programming and artifical intelligence.

In computer programming, Perl is a high-level, general-purpose, interpreted, dynamic programming language. Perl was originally developed by Larry Wall, a linguist working as a systems administrator for NASA, in 1987, as a general purpose Unix scripting language to make report processing easier. 

Although C was designed for implementing system software, it is also widely used for developing application software.

It is widely used on a great many different software platforms and computer architectures, and several popular compilers exist. C has greatly influenced many other popular programming languages, most notably C++, which originally began as an extension to C.

Taken from Wikipedia

The recommended compiler for C Programs is the GNU C Compiler (GCC). It was originally developed as the system compiler for Unix systems but has expanded to include frontends for Pascal, Fortran, C++ and Java. It is now used as a general purpose compiler and you can download it from here(Windows users will need to consider using Cywin).

During your programming career you will need to:

• Design your algorithms, views and functions.
• Comment your code.
• Produce some technical documentation.

Imagine if you could almost buy one get two free? Well you can.

If you structure your written algorithm designs in the right way they can easily become your comments and then you can use an automated program like Doxygen to extract your documentation with code snippets for you.

Haskell is an advanced purely functional programming language. An open source product of more than twenty years of cutting edge research, it allows rapid development of robust, concise, correct software. With strong support for integration with other languages, built-in concurrency and parallelism, debuggers, profilers, rich libraries and an active community, Haskell makes it easier to produce flexible, maintainable high-quality software. - from Wikipedia & Haskell

A selection of java snippets

MySql is probably the worlds most popular database engine.

Python is a fast and easy to read programming language that is often compared to Java, Perl or Ruby. It is flexible and can run on Windows, Mac and Linux. You can build both Desktop applications and websites with it.