The open source movement began in software development. People hacking code for operating systems and Big Applications started writing the same thing, but for free, and were joined by thousands of others. They were prepared to give their labour without charge to a cause for the common good.
That's all rather abstract. In concrete terms it means you can now have everything from operating systems (Linux, Ubuntu) to office suites (Open Office) and media software (Gimp, Audacity) completely free of charge.
More than that - the software is regularly updated (free again) and it probably even updates itself automatically. So you can't lose.
At the same time, there have been two other developments in technology which have had a profound effect on the way business is conducted in the digital age.
The first of these is that more and more people conduct business transactions over the Internet.
The second is that .if something can be digitised (book, picture, music) and can be downloaded - then there's no real reason why it shouldn't be free. WIRED editor Chris Anderson argues quite persuasively in his recent book FREE that modern businesses have shifted to a model whereby the basic goods are given away - free of charge. The business then makes money out of selling supplementary services.
Pop bands release their songs as free MP3 downloads, but then sell well-packaged CD versions containing extra tracks and videos of live performances. Airlines sell flights for next to nothing - but then make their money selling you coffee and Hello magazine. Software companies give away copies of operating systems such as Linux and Ubuntu - but then make their money in offering support services.
So far this model has not affected book publishing - which is notoriously conservative in its methods. But now two things are obvious. One, that a physical printed object is only one form a book might take. Second, that publishers (and individual authors) can go down this same route of the digital revolution - if they have the inclination and courage. Cory Doctorow has recently taken this step - even with a literary genre as (semi)traditional as science fiction. His basic text is released free of charge. You download it as a text file or a PDF. In both cases you can read the text on screen - free of charge. But if you want the comfortable feeling of a printed book to hold in your hands, then you have to pay - though not much.
And if you want the book printed in some glamorous fashion, with lots of extras, you have to pay a little more. Then if you want the super-delux hardback edition, which has a memory stick embedded in the cover - there's a premium to pay.
All these variations are possible because of another recent technology - print on demand. It's now possible to produce quite small print runs of books (with runs as small as just one) so long as the source code is digitised.
All of this adds up to what I am calling Open Source Publishing.
If you've written something, it's quite obvious that you can put the text on the Web for the whole world to see. You can circulate news of that publication as widely as you wish. But you can also make that text available to anyone who wishes to download it - and simultaneously profit from your labours by selling versions in other formats which some people might prefer.
All of this might seem slightly amateurish and homespun compared with the multi-million pound earnings and the best-selling sales of celebrity authors.
But they are the exception. Most writers earn very little from the books they write. The average earnings of most full time writers are about £5,000 per annum - which when you spread that over a normal working day is less than the minimum wage in the UK. In financial terms, you are earning less than a domestic cleaner. In fact you are earning roughly £2.50 per hour.
More on this shortly.