Oulipo (pronounced oo-lee-PO) stands for “Ouvroir de littérature potentielle”, which translates roughly as “workshop of potential literature”. It is a loose gathering of (mainly) French-speaking writers and mathematicians, and seeks to create works using constrained writing techniques. It was founded in 1960 by Raymond Queneau and François Le Lionnais. Other notable members include novelists like Georges Perec and Italo Calvino, poets like Oskar Pastior or Jacques Roubaud, also known as a mathematician.
The N+7 method Replace every noun in a text with the noun seven entries after it in a dictionary. For example, “Call me Ishmael. Some years ago…” (from Moby Dick) becomes “Call me islander. Some yeggs ago…”. Results will vary depending upon the dictionary used. This technique can also be performed on other lexical classes, such as verbs.
Queneau's Cent Mille Milliards de Poèmes (Hundred Thousand Billion Poems) is inspired by children's picture books in which each page is cut into horizontal strips which can be turned independently, allowing different pictures (usually of people) to be combined in many ways. Queneau applies this technique to poetry: the book contains 10 sonnets, each on a page. Each page is split into 14 strips, one for each line. The author estimates in the introductory explanation that it would take approximately 200 million years to read all possible combinations. online version
A lipogram is a kind of writing with constraints that consists of full paragraphs or books in which a particular symbol, such as that fifth symbol of Latin's script (which is most common in writing), is missing. A lipogram author must submit to an awful handicap, allowing only consonants and A, I, O, U, and Y. This is ordinarily a quorum of six fours plus half of two.