Do you speak Anglish?
I have known for a long time about L’Académie française, the French organisation dedicated to keeping the French language pure. They are an official body that act as an authority on the language, allowing or disallowing words into official usage.
Something I just learned about, though, is an English language purism movement often known as Anglish. The language is based around the idea that English should have remained with its Anglo-Saxon roots, and doesn’t use words from Greek or the romance languages. In the past it was thought that using too many words from Latin and Greek was pretentious, and so began the use of Anglish.
Uncleftish Beholding was a scientific text on atomic theory written almost entirely using Anglish, and used such words as firststuffs (chemical elements), sourstuff (oxygen), ymirstuff (uranium), bulkbits (molecules), bindings (compounds), and several other terms important to uncleftish worldken (atomic physics). I can’t imagine using these words when talking about science, but I guess it could have happened in an alternate reality.
For more examples of Anglish, have a look at http://anglish.wikia.com/wiki/Headside.