OrderedCollections.jl
This package implements OrderedDicts and OrderedSets, which are similar to containers in base Julia.
However, during iteration the Ordered* containers return items in the order in which they were added to the collection.
It also implements LittleDict which is a ordered dictionary, that is much faster than any other AbstractDict (ordered or not) for small collections.
This package was split out from DataStructures.jl.