These two sites are incredibly useful if you want to choose or understand an open licence for some software:
From these sites you can see just how many different open licence variants there are. Despite this, there are just a few that are commonly used, as shown in the ‘Most Popular’ column on the tldrlegal site.
The following link is to a very interesting post on open data licensing for governments:
The article is well worth a read. One of the interesting things that I learnt was that there is a licence for public domain data (see link) – I probably should have already been aware of this, but it was a new one for me. The article lays out 10 recommendations that government data providers should consider. These are summarised below, but I think that you should look at the original article too:
- Does the data need to be IP protected?
- Use standardised open licenses as a first choice.
- Open government licenses should contain the least restriction necessary.
- Specifically state what data the license refers to.
- Publish open licensing details next to the data.
- Maintain the links to licenses.
- State the license version.
- Avoid restrictive clauses.
- Avoid confusing and contradictory copyright notices on linked websites.
- Make clear to end users when data is in the public domain.