Remembering Carl Hewitt
December 8, 2023

Carl Hewitt changed how computer scientists build systems from independent participants. His Actor Model, object-capability work, edge-computing vision, and incompleteness robustness gave distributed software a language of messages, authority, locality, and resilience.

For Brian Greenforest, Hewitt also became a friend, a direct intellectual connection, and a twenty-year source of inspiration.

A Life Inside the Architecture of Actors

Brian followed the Actor Model from 2003, learned Hewitt’s central role through Grigory Petrov in 2008, and later built high-performance actors with queued IOCP messages and metaprogrammed delegates.

He met Hewitt in person near the Googleplex in 2019 and joined the Friday-morning object-capability community known as FriAM. Hewitt’s Citadels work placed compute, inference, and storage at the edge for low-latency augmented reality.

The Ideas Continue to Build the Future

Actors isolate state and communicate through messages. Object capabilities make authority explicit, while incompleteness robustness lets large systems continue useful work without pretending that every participant knows the entire world.

Hewitt died on December 7, 2022, at age 78. His conceptual insulation, reactive simplicity, and insistence on scalable agency continue through the systems and people he shaped. Carl Hewitt remains loved and remembered.

Originally posted on LinkedIn

Brian Greenforest · (2023-12-07 05:30:19 UTC)

Open the original LinkedIn post · LinkedIn share 7138399304351678464

LinkedIn status when archived: Visible to anyone on or off LinkedIn.

Archive note: The selected archive activity was a repost of Brian Greenforest’s original LinkedIn share; this citation uses the earlier source.

My good friend and inspiration of the last 20 years since 2003 in everything I did computer science-related, was, and forever will be Carl Hewitt, died a year ago, on December 7th 2022. Carl is most known for his advocacy for the Actor Model, work on Citadels (compute, inference, and storage at "edge" to enable AR industry with low latency and high bandwidth). I met Carl in Mountain View, at Google building where the Object Capabilities group meets in person and online for many years now every Friday AM, at 10 AM, be precise. The group is thus called FriAM. I was a huge fan of the Actor Model since 2003, but in 2008 I learned from Grigory Petrov that Carl Hewitt was the main popularizer and core computer scientist behind it. Actor Model today is everywhere, from Erlang and Scala's Akka to best practices in programming. We wrote the coolest actors with Grisha, queueing messages over IOCP and writing metaprogramming template delegates. But what most important was the William James' theory of initiation over handshakes with your professor. Direct quantum entanglement with the deepest minds in human history. Carl Hewitt was my direct connection with Isaac Newton (details in comments). First time I met Carl at a Starbucks near Googleplex in Mountain View in 2019. I will never forget that moment. ☕️😍 You are loved ❤️ and remembered forever. 🙏Your proper concept insulation, reactive modeling simplicity, and perfect Object Capabilities will live forever and will change our lives. Incompleteness Robustness is the obvious violation of Gödel's Incompleteness that allows us to build large complex and scalable systems, that Carl pioneered recently. His work continued until his last breath. R.I.P. Carl Hewitt, 1944-2022

Original LinkedIn media

Media shown with Brian Greenforest's original LinkedIn post
Photo attached to the original LinkedIn post. Open the saved full-resolution image.

Comments added by Brian Greenforest on LinkedIn

These 2 comments were also preserved verbatim from Brian Greenforest’s LinkedIn data export or the public post page. All 2 attached images are localized below.