Exploring the Design Space for Runtime Enforcement of Dynamic Capabilities

Dala is an "as simple as possible" concurrent object-oriented language designed to avoid data races. Dala objects come in three safe flavours: immutable, isolated, and local, plus a fourth unsafe flavour. The objects are organised into an hierarchy so that e.g. immutable objects can be accessed from anywhere but never mutated, while thread local objects can be mutated but cannot be accessed outside their containing thread.