Until I write better docs you can think of this package as an extension of AxisIndices's AbstractAxis to support offset based indexing.
The only unique types created in this package are subtypes of AbstractAxis.
The exported OffsetArray is just an alias for AxisIndicesArray with all axes being an OffsetAxis.
Yes this package is redundant with OffsetArrays.jl. However, it utilizes the traits in AxisIndices.jl to facilitate indexing instead of a combination of custom ranges and array types. This means that auto-centered arrays are also going to soon be available with minimal code soon. It also means that if a bug is fixed in AxisIndices.jl that the array should work here too. In other words, it should result in less code to maintain in the long run and relying on a consistent dependency that will get more attention for bug fixes.