Introduction to Data Technologies is made available under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 New Zealand License.
Creative Commons License

This licence means that you are free to copy, modify, and redistribute all or part of the material, without asking permission from the author (or from the publisher of the printed version), as long as you acknowledge the author and as long as you do not try to make money from the copies or modified material and as long as you redistribute any copies or modified material under the same conditions.

Some explicit consequences of the licence are:

Part of the reason for choosing this licence is to take full advantage of the potential-for-good of electronic formats and the internet. To paraphrase Eblen Moglen, given the opportunity to spread the information anywhere on the planet, essentially for free, what possible reason can you give for not doing so? *

The reason for the "non-commercial" and "share-alike" clauses of the licence is to provide some incentive for a major publisher to agree to produce print copies (though the intention is to limit the duration of these restrictions; see below).

Another part of the reason for choosing this licence is as a reaction to the fact that copyright has become perverted from its original purpose (which was to provide a limited monopoly for creators in order to promote creative works for the good of society). As a further (largely symbolic) step along these lines, the material will be re-released under a simple Creative Commons Attribution Licence (i.e., the non-commercial and share-alike restrictions will be removed) 14 years after the publication of the print version (the default otherwise is for the original licence to persist for at least 50 years after the death of the author!).

If you want to read, hear, or view more information about the ills of modern copyright and some of the interesting solutions being proposed and employed, there is a set of links to more detailed and/or entertaining presentations on these topics.

* One possible answer to the question "what possible reason can you give for not doing so?" is "because I cannot feed my family with warm fuzzy feelings". It should be acknowledged that this licence is particularly appropriate for scientific or technical information that is produced by someone as part of their normal employment (e.g., academic publications) and it does not necessarily generalise to other (commission-only) creative work.