The Hallway Track
Engineering Insights

Devtools must be open source (exe.dev)

Simon Willison · Aug 03, 2026 · Engineering Insights

LLMs have made open source's promise of user-modifiable software practically feasible for the first time

“I think LLMs have changed that equation in a way that makes the original dream much more feasible.”

Simon Willison argues that LLMs have fundamentally lowered the friction of exploring unfamiliar codebases, making the long-standing open source ideal of user-modifiable software newly realistic. Where compiling and understanding foreign code once required prohibitive time investment, tools like Claude and Codex now make it a near-zero-effort starting point. This is a practitioner-level signal about shifting developer behavior, though framed as personal observation rather than data.

open-source llms developer-tools ai-assisted-programming simon-willison

Watch / read the original source →