V1.0.0 betaOSS
Dr. Rocket is a Racket IDE written in Rust. It runs every DrRacket language level, steps through code exactly like DrRacket’s stepper, and adds a Visualizer that draws your program as it runs.
Requires Racket: get it at racket-lang.org. Free for macOS, Windows and Linux.
DrRacket is the reference, and Dr. Rocket runs Racket’s own stepper, check syntax, debugger and test engine under the hood. What’s new is everything around them: a GPU-rendered editor, a file tree, tabs, a command palette, integrated terminals and themes.
Run a program and replay it one step at a time. Every call gets a frame, trees and lists are drawn as real diagrams, and each step is explained in plain words while its code lights up in the editor.
Arguments and locals for each call. Tail calls replace their caller’s frame, as Racket runs them.
Structs that point to their own type become trees, cons cells become chains, and both glide as they change.
“Is (empty? t) true? Yes.” Each step says what happened and why, so recursion stops being magic.
See every reduction before and after, mirrored in your source. Dr. Rocket drives DrRacket’s own stepper, so you get the same steps your course notes show, cons chains printed as lists, images drawn inline, all the way to the final value.
Check syntax runs in the background: arrows from each binding to its uses, unused bindings, hover info, rename and go to definition across files. Set breakpoints in the gutter and step into, over and out with locals and the call stack. The profiler, test coverage and macro stepper are here too.
Files saved by DrRacket open with their images inline, run with real images, and save back in DrRacket’s format, so you can switch back at any time. Paste images straight from the clipboard, or use Insert Image.
Keep each course open as a project tab with its own files and layout. Run raco in an integrated terminal, search the whole project, jump to any file with ⌘P and reach every command from the palette.
The default, Moiz One Dark, matches Zed’s One Dark Darker exactly. One Light, GitHub Light, Catppuccin, Gruvbox, Tokyo Night and DrRacket’s own colours are built in, and every Zed theme you have installed shows up too. Code is set in Fira Code, with ligatures and rainbow brackets.
-> => >= <= != λ
Pick a level just as you would in DrRacket. Teaching-language files keep DrRacket’s header, so they open in either IDE, and output style, fraction style, tracing and teachpacks come along.
#lang racket, and any #lang
Dr. Rocket is the editor; Racket runs your programs. Any recent Racket works and we test with 9.3. If you have DrRacket, you already have it. Otherwise, get Racket at racket-lang.org.
Universal DMG, Apple Silicon and Intel · 22 MB
Dr.Rocket-1.0.0-beta.1.dmg and drag Dr. Rocket into Applications.64-bit zip, no installer · 11.5 MB
Dr.Rocket-1.0.0-beta.1-windows-x64.zip.Dr. Rocket.exe from the Dr. Rocket folder.x64 tarball with a desktop entry · 12.1 MB
tar xzf Dr.Rocket-1.0.0-beta.1-linux-x64.tar.gz"Dr. Rocket/drrocket".drrocket on your PATH and copy drrocket.desktop to ~/.local/share/applications.Dr. Rocket finds Racket on its own. If it says “Racket not found”, set the path in Settings, then Racket.
Yes. Dr. Rocket is the editor, and Racket runs your programs, the stepper and check syntax. Any recent version works; we test with 9.3. If you have DrRacket, you already have Racket. Dr. Rocket looks for it on your PATH, in Homebrew, in /Applications/Racket* and in C:\Program Files\Racket. Otherwise, get it at racket-lang.org.
Yes, including files with pasted images and comment boxes. They run with real images and save back in DrRacket’s format, so you can reopen them in DrRacket. A few rare boxes (XML boxes, Racket boxes, test-case boxes and large letters) make a file open read-only, so it’s never damaged.
Yes. Dr. Rocket is free to download and use. It’s made by Moiz and John.
Yes: there’s a 64-bit Windows zip, a Linux x64 tarball and a universal Mac app. The full test suite runs on all three in CI. Most day-to-day use so far has been on macOS, so reports from Windows and Linux are especially welcome.
Because the beta isn’t code-signed yet. On macOS, right-click the app and choose Open the first time (or use Open Anyway in System Settings, Privacy & Security). On Windows, click More info, then Run anyway. You only need to do this once.
If your course uses DrRacket’s teaching languages (Beginning Student through Advanced Student, or DeinProgramm) or #lang, yes: every level is there, with the same output and fraction settings and teachpacks. One caveat: DrRacket plugins, like a course’s handin Submit button, don’t run in Dr. Rocket, so submit the way your course allows outside DrRacket, or from DrRacket itself.
It drives DrRacket’s own stepper, and we check it against DrRacket on the same files: step for step, including cons chains shown as lists and the closing step. As in DrRacket, Advanced Student, the advanced DeinProgramm level, R5RS and Pretty Big have no stepper.
Free for macOS, Windows and Linux.
Requires Racket: get it at racket-lang.org