The post is about CeeLite - http://www.ceelite.com/
The company makes flat sheets that lite up. The largest size is 3'x6' but there is a wide variety of sizes available. The product is flexible, printable, and dimmable. Though it is somewhat costly, it allows for light in places that would not be possible using normal fixtures. It can operate through DMX for programmable effects. The website has alot of information, as well as downloadable documentation. While I have seen this product used more for trade shows, I have seen places where it would be effective in theatre; particularly for displays, and potentially for floors or built into flats for windows, ect.