Easel Turns One One year of building my own IDE in Clojure

Summary

Posted: December 20, 2025What is Easel?Easel is an IDE written in Clojure that I've been working on for the last year. See it in action https://youtu.be/sceGtaNHxcM.Easel itself is relatively focused. It provides a model for specifying tools and a simple user interface for arranging tools in the same window. The bulk of the functionality you would expect from an IDE is provided via simple, modular tools that can share data with each other. Tools can also be used independently outside of Easel. Think of it as an IDE as a library. Some examples of tools are text editing, terminal emulation, data inspection, web browsing and more.Why Easel?Imagine it's 10 years from now and you're working in the IDE of your dreams. What would that look like? For me, it would be something like the following:The IDE can be extended at runtime using ClojureStrong support for REPL-driven development (ie. work on your program while it's running)Direct access to data. Lots and lots of tools to visualize, summarize, search, transform, and interact with data2d, 3d graphicsData orientation over text orientationProvide a platform for experimentationSituated tools that work together by sharing dataIDE as a libraryUser orientedOpen sourceFull access to the capabilities of the hardwareThe Hard ProblemsYou may notice that none of the items on our wishlist are revolutionary. In fact, all of them exist as features in popular IDEs from today and yesteryear. However, there isn't an IDE that has all of these features. If my goal was to have a demo as soon as possible, I would look at the available options and start building on whichever option checked the most boxes. However, my goal isn't to have most of these features. I want them all! With that in mind, I oriented my search for a foundation based on the hardest problems.The foundation that I chose was to build Easel using Clojure, running on the JVM. The JVM solves many hard problems that would likely take decades to solve for other foundations. Some ...