A new file format, a new free software supporting this kind of format, was presented by the German chapetr of WWF to the public.
This green file format is a kind of pdf that allows you to save a document as a file that literally cannot be printed out.
The software is a free download, and is compatible with Macs, though a Windows version is on its way. When choosing a file format for saving a document, you simply select WWF, and it does the rest.
For further information just click here.
(via : treehugger)