isn't what we use VanitySearch for? Or by 'to generate key for address' you mean to generate private key for a given address?
Aaa, you mean Kangaroo program by Jean Luc? It is just an another approach to find private key which generates given address. Recently the discussion in the topic is mostly theoretical, how to improve algorithm. On github of this project Jean Luc mentioned some documents/papers which you may want to read to learn more about this way of solving problem.