Home

Welcome Visitors!

Let's build a Pattern Language for object capability (ocap) patterns, especially their use in secure JavaScript and Rholang.

• CareTaker
• SealerUnsealer
• PetNames
• NotaryInspector
• CoatCheck

E in a Walnut by Marc Stiegler in 2000 is one of the earliest and best works containing a selection of ocap patterns.

The A Rholang tutorial by Mike Stay and the rchain core team in 2018 shows how to use several of them in Rholang.

What about [my langauge]?

If your language has memory safety and encapsulation, and you can keep the global namespace to immutable data, you should be able to use object capability discipline.

• DisciplinedPython is a convention for using ocap discipline in python.
• Monte is another ocap language in the tradition of E and python.
• Joe-E showed how to do it in Java in 2008
• Emily was a 2006 project for ocaml. See also Ocaml and Emily in a Walnut.

See the Programming Languages section for pony, scala, scheme (racket), and more.

CapnProto can be used for cross-language interop within or between processes. Likewise, CapTP goes between vats.