# Xo v0.7.0

First tagged release. Spec draft 0.7.

- Language: request scoped arenas by default, `use go` packages, two
  phase shutdown, `Mutex.with_read`, `BytesBuilder`, rune and integer
  conversions, native contracts and fault unwinding, habit diagnostics
  (XO0177), `clock.sleep_or_cancel`, cancellable stdin, tuple JSON,
  `Duration.parse` (decisions 0041 to 0088).
- Backends: Go (default), LLVM, native arm64, `--no-gc`, `--hybrid`.
- Toolchain: `xo version`.
- Planned before 1.0: modules and workspaces (0086), `std/time`, native
  TLS, and decisions on the Appendix B questions.