Reliable, freely available data is an important building block for the workings of a modern society. One of the Appleseed goals is to Educate about Open Data, with its advantages and limitations.
A common factor of these sources is their transparency, open contributions, open history, contribution rules and culture.
Wikipedia
There is much more to Wikipedia than the page about a subject. Every page has a ‘History’, which preserves all the changes which have been made to that page.
It is possible (and fairly easy with access to a Linux server), to run a local copy of Mediawiki (the underlying software). Schools could run their own copy, to allow pupils to experiment with creating pages, updating other peoples pages, reverting vandalism etc.
OpenStreetMap
I think that I shall never see
A billboard lovely as a tree.
Indeed, unless the billboards fall,
I’ll never see a tree at all.“Song of the Open Road” – Ogden Nash
Maps which are free to use, but funded by advertising have to generate income to pay for them, plus a profit margin. This tends to lead to them being way to get customers to event venues but not everyone’s lives are centred around shopping.
We travel not for trafficking alone;
By hotter winds our fiery hearts are fanned;
For lust of knowing what should not be known,
We take the Golden Road to Samarkand.“Hassan” – James Elroy Flecker
If you are mapping the world for scientific, or humanitarian purposes (such as the Humanitarian OpenSteetMap Team) then having others able to build on, or update, your work may fit your goals better.
GIT
Most Free Software projects now run in a GIT repository, which is a way of making their source code available,
People considering a career in IT can create an account in one, or more of the large git repositories, and contribute to projects. Their contributions are then visible to potential employers.