Language fronts

40 parser fronts route into one Core IR pipeline. Authoritative matrix:

in languages
in languages --json

First-class

Language	Extensions	Front	Capabilities
inlang	`.in`	`in_lang_parse`	parse, lower, typecheck, boundary
icore	`.icore`	`compiler::icore`	parse, lower, typecheck, boundary
Rust	`.rs`	`compiler::rust_front`	parse, lower, typecheck, boundary
V	`.v`	`compiler::tree_front`	parse, lower, typecheck, boundary

Tree-sitter polyglot (selection)

Swift, Go, C, C++, Objective-C, Java, JavaScript, TypeScript, Python, Ruby, Zig, PHP, Kotlin, Scala, C#, Nim, D, Haskell, OCaml, Lua, and more—see in languages --json for the full list, example paths, and maturity gates.

Resolution: extension map, IN_PARSER, #!in parser=… — parser-surface.md.

Runtime boundary

Owned path is JIT / native_emit on AArch64 and x86_64. External toolchains (rustc, swiftc, …) are optional parity checks in in test --external-parity, not the default execution engine.