OpenJai is an open source implementation effort for a Jai-style systems programming language and compiler. The project is guided by docs/open_jai_spec.md, with the current bootstrap compiler implemented in Zig under bootstrap/.

The goal is to build a fast, ahead-of-time compiled, low-level language for game programming, general-purpose systems work, and metaprogramming-heavy development. OpenJai is intended to prioritize developer productivity first, then performance, then safety.

This repository currently contains an early Zig bootstrap compiler. It is not yet the final self-hosting OpenJai compiler.

The bootstrap compiler has the start of the full pipeline:

source -> lexer -> parser -> AST -> semantic analysis -> bytecode -> LLVM object -> linked executable

Current support is still incomplete, but the bootstrap compiler now covers a large example-driven surface, including compile-through checks for the example corpus. The complete language described in the spec remains work in progress.

bootstrap/   Zig implementation of the bootstrap compiler
src/         Jai port of the bootstrap compiler, kept structurally aligned
docs/        Language spec and compiler implementation notes
examples/    Jai/OpenJai example programs used as compiler milestones
test/        Jai-style test framework and example-derived tests
out/         Generated build output, ignored by git

Important docs:

• CONTRIBUTING.md: clean-room contribution rules.
• docs/public_sources.md: public-source bibliography and provenance guidance.
• docs/open_jai_spec.md: language goals and specification notes.
• docs/OpenJai_implementation_notes.md: bootstrap compiler architecture and implementation plan.
• docs/open_jai_test_spec.md: Jai-style test framework design and example-test conventions.

The current bootstrap build expects:

• Zig 0.16
• LLVM installed under /usr/local/llvm
• /usr/local/llvm/bin/llvm-config
• /usr/local/llvm/bin/clang++
• macOS SDK tools available through xcrun

The language goals include broader platform support, but the current bootstrap build script is wired to this local LLVM/macOS toolchain.

Build the bootstrap compiler:

make bootstrap

This writes generated files under out/:

out/bootstrap/bin/openjai
out/bootstrap/lib/openjai_runtime.o
out/zig-cache/

Build the current staged compiler chain:

make build

Today this means:

stage0: Zig bootstrap seed
stage1: Jai compiler source built by stage0

The Makefile also defines the later self-hosting checks:

make stage2
make stage3
make fixpoint

These are intentionally strict and are not expected to pass until the Jai-built compiler can compile src/main.jai. make fixpoint byte-compares the stage2 and stage3 compiler outputs once both stages exist.

Build the currently supported example subset:

make examples

make examples checks every *.jai file under examples/ by default. Generated outputs are written under out/examples/, mirroring the source tree.

Run all repository tests:

make test

This runs the Zig bootstrap tests, the example compile sweep, and the Jai-style test harness.

Check the Jai source port:

make selfhost-check

The Jai compiler port lives under src/ and mirrors the Zig bootstrap compiler module boundaries. The Zig bootstrap compiler remains the trusted compiler until the Jai port can compile examples/hello.jai end-to-end.

Clean generated output:

make clean

After make bootstrap, compile a supported source file with:

out/bootstrap/bin/openjai examples/03/3.1_hello_sailor.jai \
  -o out/examples/03/3.1_hello_sailor \
  --runtime out/bootstrap/lib/openjai_runtime.o

The compiler CLI is currently:

openjai <input.jai> [--check] [-o output] [--runtime runtime.o]

make examples runs the broad compile-through acceptance sweep for the example corpus. The SUPPORTED_EXAMPLES list is discovered dynamically from examples/**/*.jai.

You can also override the example list:

make examples EXAMPLES="examples/03/3.1_hello_sailor.jai examples/05/5.1_literals.jai"

The project has two layers of tests:

• make test-bootstrap: Zig unit tests for the bootstrap compiler.
• make test-jai: Jai-style tests described by docs/open_jai_test_spec.md.

Use make test for the full local suite.

Build products are intentionally kept out of the source tree and ignored by git:

• out/
• **/.zig-cache/
• **/zig-out/
• **/.build/

Generated artifacts should go under out/, not next to source files.

Zig cache policy:

• build.jai centralizes Zig caches under out/zig-cache/ and prunes stale object-cache hashes automatically before Zig bootstrap builds.
• Use openjai build.jai ... - cache-clean to remove all centralized Zig caches plus legacy bootstrap/.zig-cache artifacts.
• Avoid raw cd bootstrap && zig build; Zig will create a second cache at bootstrap/.zig-cache. If a direct Zig command is required, pass --cache-dir ../out/zig-cache/bootstrap --global-cache-dir ../out/zig-cache/global.

The OpenJai compiler is MIT licensed.