  Concurrent and parallel programming is difficult due to the presence of
memory side-effects, which may introduce data races. Type qualifiers, such as
reference capabilities, can remove data races by restricting sharing of mutable
data. Unfortunately, reference capability languages are an all-in or nothing
game, i.e., all the types must be annotated with reference capabilities. In
this work in progress, we propose to mix the ideas from the reference
capability literature with gradual typing, leading to gradual reference
capabilities.
