By an overwhelming margin, ZDNet readers have voted 'two point oh' the preferred way to say '2.0' in phrases including Web 2.0, Business 2.0, Enterprise 2.0, Office 2.0 and so on.
Why would there be any doubt about this? '2.0' is clearly a version number with a decimal point in it, and therefore it's self-evident that the separator between the two numbers is pronounced 'point'.
The confusion stems from the use of the word 'dot' by American speakers of English in phrases such as 'dot com',How to say 2.0, $3.49 and 802.3 'dot net' and so on. This is not common usage in Britain, and therefore people throughout the world who have been taught English by British English speakers are unsure when to say 'dot' and when to say 'point' — because their teachers were themselves unfamiliar with the usage. Come to think of it, the rest who were taught by American English speakers may be equally unsure, because their teachers never thought to mention it and it's not spelt out in any textbooks.
So while educated native speakers of American English intuitively know when to say 'dot' and when to say 'point', the rest of us have been rather in the dark. Here for the record, then, are the rules about when to use 'point' and when to use 'dot':
- Use 'point' when you're talking about a decimal point in a number, eg version 2.0 or 16.9 percent (but not when the number is a sum of money, and if the position of the decimal point is obvious from the context, eg if your cup of coffee costs $3.49, you'll be asked for 'three forty-nine'). As with the money exception, it is also accepted usage to say just 'two oh' if the context makes it evident that what you mean is '2.0';
- Use 'dot' when you're talking about a separator, whether between letters or numbers, eg a web address like zdnet.com is said 'zdnet dot com', and similarly a numeric IP address like 192.168.1.1 is said '192 dot 168 dot 1 dot 1'. This rule also explains why the name of an IEEE standard like 802.11 (WiFi) is spoken with a dot rather than a point: as one commenter posted in response to my poll, "the IEEE stuff usually ends in a letter, but yes, also a dot for specs that don't end in a letter like ethernet, 802.3."
As well as 'two point oh', other ways of saying the number 0 are allowed, such as 'two point zero' or (if you're British) 'two point nought'. But 'two point oh' is normal usage on both sides of the Atlantic, so it's the safest choice if you're unsure which to say when.
Remember that in other contexts, '.' has other names. At the end of a sentence, it's a 'period' in American English and a 'full stop' in British English, shortened to 'stop' in telegrams. And in banking, people say 'spot' when quoting exchange rates (eg '1 spot 9522 pounds to the dollar'). There are probably other examples I'm not aware of.
In writing this, I'm conscious that I should acknowledge my debt to one of my university teachers, Professor Randolph Quirk (now Baron Quirk), who established the Survey of English Usage at University College London, and who taught me all I know about the use of English. If you were wondering how a degree in English helps me write about technology, now you know.