I had never heard of it either, but it’s a French acronym, short for Ouvroir de littérature potentielle; roughly translated: “workshop of potential literature”). You can read up on it here. We studied it recently in a class I’m taking on the structure of poetry.
The most well known of these, S+7, suggests that you take every important noun (or verb) in your poem, and replace it with the word that comes seven words after it in the dictionary. “I wandered lonely as a cloud” would become (using the closest dictionary to hand, and skipping all the cloud words like cloudiness, cloudy, etc.), “I wandered lonely as a clown.” You can see the possibilities. I think of it as a tool to try to get some fresh ideas into your work.
Another technique is to simply eliminate every x-number of words. I did this recently (and eventually unmathematically) with an article from the NY Times a few weeks ago. All the words are words in the original article, and they all appear in the order in which they appeared. I copied the article, then changed the font to white for many words. Then I gave up on math and whited out a whole bunch more words, which gave this particular spacing:
* * *
The Banality of Robbing the
38,000 apartments 674 trains to transport
toys dishes family photos tools light bulbs pianos porcelain fine linens
A saucepan from one family added to a stack of saucepans
xxxxxxxxxxxxxxxxxxxxxx too Jewish?
xxxxxxxxxxxxxxxxxxx fit for use by Aryans?
xxxxxxxxxxxxxxx they would come to shop
xxxx damaged personal daily bonfire
xxxxxxxxxxxxxxxx xxxxxx all trace
* * *
I found the process interesting. In any case, now you know a little about Oulipo. The only writer’s name I recognized was Italo Calvino, whose work I’ve always found strange and wonderful.