In the field of ecology, the relative abundance distribution (RAD) is a graph of the number of species observed in a field study as a function of their observed abundance. The graphs obtained in this manner are typically fitted to a Zipf-Mandelbrot law, the exponent of which serves as an index of biodiversity in the ecosystem under study.
Lettris is a curious tetris-clone game where all the bricks have the same square shape but different content. Each square carries a letter. To make squares disappear and save space for other squares you have to assemble English words (left, right, up, down) from the falling squares.
Boggle gives you 3 minutes to find as many words (3 letters or more) as you can in a grid of 16 letters. You can also try the grid of 16 letters. Letters must be adjacent and longer words score better. See if you can get into the grid Hall of Fame !
English dictionary Main references
Most English definitions are provided by WordNet .
English thesaurus is mainly derived from The Integral Dictionary (TID).
English Encyclopedia is licensed by Wikipedia (GNU).