Not so long ago, typing was for secretaries, journalists, and would-be authors. Now we're all tapping away at keyboards and screens from morning until night.
The number of people who spend their workday coding continues to soar. In the not-too-distant future, writing code may be as commonplace as typing and other forms of text-keying are today.
Learning how to code has never been easier. Whether you're a programming newbie or an old hand looking to learn a new skill or two, these four free services have you covered. (Note that all but W3Schools.com requires that you register to use the service by providing an e-mail address and password.)