Download Mycel
This is the first version you can install: Mycel 0.1 alpha. One installer gives you mycel, which runs your programs, and ply, the package manager. It's free to use, and you don't need anything else installed.
It's an alpha, and the installer isn't signed with an Apple Developer ID yet, so macOS will warn you the first time. After the warning, open System Settings → Privacy & Security and click Open Anyway next to the Mycel installer. Intel Macs, Windows and Linux aren't supported yet.
Your first program
Once it's installed, open Terminal and try this:
$ echo 'print("hi")' > hello.myc $ mycel hello.myc hi $ mycel new my_app # a whole project with tests $ cd my_app && mycel run && mycel test
New to Mycel? The learn page walks through it, and the playground runs the same compiler in your browser.
What works, and what doesn't yet
Works: the whole language (f-strings, classes, enums and match, errors that tell you what to type), tests, formatting, a REPL, Mycel's own packages through ply, and the editor plugins for VS Code and JetBrains IDEs.
Not yet: importing Python or npm packages (ply install --py is understood but doesn't install anything yet), and the UI and database libraries. Expect some rough edges; it's an alpha.
Uninstall
$ sudo sh /usr/local/share/mycel/uninstall.shLicense
Mycel is free to install and use, including for your own commercial projects, and programs you write in Mycel are yours. The compiler itself is proprietary: copyright 2026 drky, all rights reserved. Read the full license.