Echo is a compiled language.

Statement leaders mark control and binding. The rest of each line is an ordinary expression. xo checks a program and emits a native binary from the same LLVM pipeline.

Echo 2026 is the public edition. A Rust toolchain ships as prerelease tags on GitHub. The repository is MIT licensed.

/ std/io

$ xs = [1, 2, 3]
~ sum = 0
* x : xs {
    ~ sum = sum + x
}
io.print("sum={sum}")

Start

Build xo and write a first program.

Install Install the current xo prerelease, or build from a checkout.
First program Minimal runnable shape and the xo check, run, and build commands.
Project setup Create an entry file and a local workflow.

Language

Statement forms for the Echo 2026 edition.

Leaders Statement leader forms. A glyph marks the role of each statement.
Binds and functions Immutable, mutable, and const binds. Functions are values.
Values and operators Literal forms, operator precedence, equality, and copy.
Collections and ranges Lists, products, indexing, and inclusive ranges.
Control If, loops, match, break, and continue.
Result and option Produce and match result and option shapes.
Strings Pure and rich string forms.
Modules and std Imports, exports, and the std/ import policy.
Structs % shape, @ members, and the method receiver.
Tasks Spawn work, capture values, and join task handles.

Packages

Userland modules imported as std/ paths.

Standard library Userland modules for I/O, strings, files, process, JSON, encoding, crypto, collections, and networking.
API reference Index of public exports across shipped std modules.

Spec

Public language law and the machine-checked suite.

Echo 2026 Edition home for the current public language.
Language Spec Spec table of contents mapped to the Reference and the suite.