Roadmap

mu stays minimal, self-hostable, practical, and predictable. The roadmap is a sequence of small, testable steps that keep the compiler, VM, and documentation in lockstep.

North star

• Keep the grammar and builtin surface small.
• Make the compiler and VM behavior explicit and testable.
• Keep the host self-contained while growing the stdlib in mu.
• Ensure VM and native backends agree on semantics.

Phase 0 · Consolidate what exists

• Align the spec, grammar, and docs with current behavior.
• Make stable syntax and builtin contracts explicit.
• Ensure examples run in both VM and native modes.

Phase 1 · Tooling via flags

• Add -check, -fmt, -test, and deeper compile flags.
• Keep the UX simple: one binary, flag-driven workflows.
• Make formatting deterministic.

Phase 2 · Diagnostics

• Source-aware stack traces.
• Deterministic runtime errors with locations.
• Shared test fixtures across VM and native.

Phase 3 · Concurrency + sockets

• Process, concurrency, and socket builtins.
• Verified semantics with both unit and integration tests.
• Shared .mu test fixtures across runtimes.

Phase 4 · Module system contract

• Lock down import rules, caching, and init order.
• Ensure deterministic import resolution across platforms.

Phase 5 · Self-hosting

• mu-written lexer and parser.
• A documented bootstrap flow from stage-0 to stage-1.

Phase 6 · Carefully-scoped additions

• Only expand the core if real programs demand it.
• Prefer stdlib growth in mu over adding host builtins.

Learn more

For the authoritative roadmap and acceptance criteria, see docs/Roadmap.md.

Next steps

• Read the runtime guide for VM/native context.
• Explore the standard library to see how features land in mu.
• Start with the language tour if you’re new.