Awesome
Rope
An implementation of the Rope data structure, which is useful for storing large arrays that are frequently mutated. The Rope is often used instead of a string (array of characters), but can be used to replace any kind of array. This implementation provides a Rope for arrays of bytes, but it should be easy to modify it for other types of elements (this can be made generic in future versions of Go).
See the Godoc for the available functions. Much of the implementation is based on the Rope implementation here.