[thegenius2000]

Can you clarify what you mean by "kill goroutines?" Because my understanding was if you return while inside a goroutine it get's handled by the GC immediately, and (as someone else mentioned) you can use context to send deadlines/cancellation signals to go routines.

[Manishearth]

The ability to kill an arbitrary goroutine from the outside. To use context you need to write your specific goroutine such that it checks for cancellation and will eventually handle a cancellation request. This cannot be done with an arbitrary goroutine.