Brent Simmons - Writing Mac and iOS Apps Shouldn’t Be So Difficult
2025-08-28
The app was implemented in two pieces:
- The kernel, written in C, implemented the database, networking, inter-application communication, various built-in data types, script compiler and evaluator and debugger, and so on
- The scripts used the kernel and implemented most of the actual app behavior
Since it was an app, it had plenty of UI — menus, contextual menus, buttons, larger UI components, and so on. What was brilliant was that you could, for instance, add and edit menus, and when you chose a menu command it would run your script. (Or when you clicked a toolbar button, etc.)
You could write an entire static blog publishing system and the UI to go with it without ever restarting the app. Click a thing, then see what happens in the app — and if it’s not right you’d edit the script, which would be automatically recompiled when called the next time.
In other words, there was absolutely no friction when it came to iteration. Write some code without restarting and see your changes immediately.
I don't usually write UI not use scripting languages but I can tell the huge difference when I am working on a small web-application I wrote in Elixir using Phoenix. Being able to immediately see the effect of new pieces of code I am writing makes for a very different experience.
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