What is open data?

If you’ve not heard of open data before, there’s a generally accepted definition that:

Open data is data that can be freely used, re-used and redistributed by anyone – subject only, at most, to the requirement to attribute and sharealike.

Or, as the Open Data Institute (ODI) put it:

Open data is data that anyone can access, use and share.

The ODI has lots more information about open data on its web site, and the Open Data Handbook from the Open Knowledge Foundation (OKFN) is also crammed full of useful information