"Whats crackin" is a slang phrase that can be used as a greeting, synonymous with greetings such as "Whats going on?" or "Whats happening?". It can also mean "how are you?" or "whats up?". The phrase has its roots in Middle English, where "crack" meant "loud conversation, bragging talk". In modern usage, "crackin" can also mean "cool," "tight," or "excellent". The phrase is often used in hip-hop music and culture.