Georges Perec's A Void was originally written in French (as La Disparition). It completely avoided using the letter "e". As you know, the letter "e" is the most common letter in the English alphabet. Without it you can't use "the", "he", "she", "love", or about three quarters of the words in English. Since French uses even more e's, I am told that that constraint excluded seven eighths of all French words from being used in the composition. The translation that was subsequently made in to English managed to keep the same constraint.

Perec did all sorts of other interesting constrained writing experiments, many in conjunction with Oulipo (a group that included Italo Calvino), who were also particularly interested in constrained writing. One of their other members, Raymond Queneau created a work called 100,000,000,000,000 Sonnets, which "consisted of ten pages of 14 lines, cut into strips so that one could lift a strip and make up to 10^14 combinations, thus the title. If you attempted to read all the sonnets contained, it would take 190,258,751 years until you finished it."