An overview of object capabilities, an access-control mechanism that composes nicely and has sensible behaviour, unlike ACLs/RBAC. Uses everyday examples to explain capabilities themselves as well as the notion of attenuation of authority. Also includes a discussion of practical considerations.

Low-level implementation details on how Fil-C, a memory-safe, capability-oriented C compiler and runtime, is able to implement function calls efficiently while maintaining strong, well-defined memory-safety invariants:

Fil-C achieves memory safety even for programs that behave adversarially. That includes casting function pointers to the wrong signature and then calling them, exporting a function with one signature in one module and then importing it with a different signature in another, or even exporting a symbol as a function in one module and importing it as data in another (and vice-versa). Passing too few arguments, arguments of the wrong type, misusing va_list (including escaping it), expecting too many values to be returned - these are all things that the Fil-C calling convention either catches with a panic or ascribes safe behavior to.

Arcan is an alternative approach to display servers and UI, drawing inspiration from object capabilities, Plan 9, malleability and much more. See also the 12 Principles for a Diverging Desktop Future blog post for an overview.

Arcan is an alternative approach to display servers and UI, drawing inspiration from object capabilities, Plan 9, malleability and much more. This blog post motivates and gives an overview of the project; see also the main project page.