#aot

AOT Compilation Case Studies: Summary for MEP-42

§1 Scope This summary distils the case studies in 01_*.md through 12_*.md : GraalVM Native Image, .NET NativeAOT, Zig self-hosted, Crystal, Nim, Hare, V, Julia/juliac, Mojo, GHC NCG, Swift / Embedded Swift, and Static Python / Cinder / CPython 3.13 JIT. Each file has its own provenance, architecture, target matrix, runtime, status, Mochi adaptation note, and open questions. This document looks only at the cross-cutting patterns. §2 Closed-world vs open-world...

Swift and Embedded Swift

§1 Provenance Project home: https://swift.org/ Source: https://github.com/swiftlang/swift Embedded Swift overview: https://www.swift.org/get-started/embedded/ "Get Started with Embedded Swift on ARM and RISC-V Microcontrollers": https://www.swift.org/blog/embedded-swift-examples/ WWDC24 session "Go small with Embedded Swift": https://developer.apple.com/videos/play/wwdc2024/10197/ Swift 6 announcement: https://www.swift.org/blog/announcing-swift-6/ Embedded Swift vision document (in-tree): https://github.com/swiftlang/swift-evolution/blob/main/visions/embedded-swift.md Authors: Apple's Swift team, with Embedded Swift led by Kuba Mracek, Alex Lorenz, and the Cupertino compiler group. Lattner was the original Swift creator (now at Modular working on Mojo)....

GHC NCG and the LLVM Backend Choice

§1 Provenance Project home: https://www.haskell.org/ghc/ Source: https://gitlab.haskell.org/ghc/ghc Backends documentation: https://downloads.haskell.org/ghc/9.12.2/docs/users_guide/codegens.html 9.12.1 release blog: https://www.haskell.org/ghc/blog/20241216-ghc-9.12.1-released.html 9.12.2 release blog: https://www.haskell.org/ghc/blog/20250314-ghc-9.12.2-released.html 9.12.3-rc2 announcement (Nov 2025): https://www.haskell.org/ghc/blog/20251111-ghc-9.12.3-rc2-released.html Well-Typed activity reports (the most consistent NCG status source): https://www.well-typed.com/blog/ Tweag's "Making GHC faster at emitting code": https://www.tweag.io/blog/2022-12-22-making-ghc-faster-at-emitting-code/ Foundational paper: Marlow et al., "Faster Laziness Using Dynamic Pointer Tagging" (ICFP 2007); the Cmm/STG split traces to the Spineless Tagless G-machine (Peyton Jones 1992). §2 Architecture GHC's pipeline...

Static Python, Cinder, and CPython's Copy-and-Patch JIT

§1 Provenance Cinder: https://github.com/facebookincubator/cinder (Meta's CPython fork) CinderX (the extension form): https://github.com/facebookincubator/cinderx Static Python documentation in-repo: https://github.com/facebookincubator/cinder/blob/cinder/3.8/CinderDoc/static_python.rst Meta's "Python 3.12 features" engineering blog (the hooks landing): https://engineering.fb.com/2023/10/05/developer-tools/python-312-meta-new-features/ CPython JIT PEP 744: https://peps.python.org/pep-0744/ Copy-and-patch paper: Xu and Kjolstad, "Copy-and-Patch Compilation" (OOPSLA 2021, https://fredrikbk.com/publications/copy-and-patch.pdf ) Authors: Cinder/Static Python by Meta's Instagram and Python infra teams (Carl Meyer, Itamar Ostricher, Dino Viehland, etc.); CPython 3.13 JIT by Brandt Bucher and Ken Jin building...

Mojo

§1 Provenance Project home: https://www.modular.com/mojo and https://mojolang.org/ Source (now public): https://github.com/modular/modular (the Mojo language tree) Documentation: https://docs.modular.com/mojo/ FAQ: https://docs.modular.com/mojo/faq/ 1.0 beta announcement: https://forum.modular.com/t/modular-26-3-mojo-1-0-beta-mojolang-org-max-video-gen-and-more/3038 "Path to Mojo 1.0" blog post (5 Dec 2025): https://www.modular.com/blog/the-path-to-mojo-1-0 MLIR foundation paper: Lattner et al., "MLIR: Scaling Compiler Infrastructure for Domain Specific Computation" (CGO 2021). Authors: Chris Lattner (LLVM/Swift/MLIR creator), Tim Davis, and the Modular Inc. team. Founded 2022. §2 Architecture Mojo's compiler pipeline is an...

Nim

§1 Provenance Project home: https://nim-lang.org/ Source: https://github.com/nim-lang/Nim Memory management reference: https://nim-lang.org/docs/mm.html 2.2.0 release announcement: https://nim-lang.org/blog/2024/10/02/nim-220-2010.html Roadmap RFC: https://github.com/nim-lang/RFCs/issues/556 Nimony (next-gen compiler): https://github.com/nim-lang/nimony NIFC dialect specification: https://github.com/nim-lang/nimony/blob/master/doc/nifc-spec.md Author: Andreas Rumpf (Araq). Project started 2008; Nim 1.0 in 2019, Nim 2.0 in Aug 2023. §2 Architecture The classical Nim pipeline (still the production pipeline as of 2.2.x in May 2026): Parser → AST. Sem pass performs type inference, generics instantiation, macro expansion...

V Language

§1 Provenance Project home: https://vlang.io/ Source: https://github.com/vlang/v FAQ: https://github.com/vlang/v/wiki/FAQ Memory management docs: https://docs.vlang.io/memory-management.html Native backend discussion: https://github.com/vlang/v/discussions/13675 Architecture wiki (DeepWiki overview): https://deepwiki.com/vlang/v Author: Alexander Medvednikov (Medvednikov), Estonia. First public release 2019, MIT license, beta in May 2026. Notable as a 2025 entrant on the TIOBE index. §2 Architecture V's pipeline: Parser → AST. The parser is hand-written and pegs single-pass single-file parsing as the performance budget. Checker does name resolution...

Julia

§1 Provenance Project home: https://julialang.org/ Source: https://github.com/JuliaLang/julia AOT devdocs: https://docs.julialang.org/en/v1/devdocs/aot/ PackageCompiler.jl: https://github.com/JuliaLang/PackageCompiler.jl , docs at https://julialang.github.io/PackageCompiler.jl/dev/ JuliaC.jl driver: https://github.com/JuliaLang/JuliaC.jl LWN coverage of the 1.12 binary-size work: https://lwn.net/Articles/1006117/ JuliaCon 2024 talk "New ways to compile Julia" by Jeff Bezanson and Gabriel Baraldi (slides linked from https://juliahub.com/blog/new-ways-to-compile-julia-blog) . Foundational paper: Bezanson, Edelman, Karpinski, Shah, "Julia: A Fresh Approach to Numerical Computing" (SIAM Review, 2017). §2 Architecture Julia's traditional pipeline is JIT-first: Parse...

Hare

§1 Provenance Project home: https://harelang.org/ Source: https://git.sr.ht/~sircmpwn/hare Specification: https://harelang.org/specification Announcement: https://harelang.org/blog/2022-04-25-announcing-hare/ Backend (QBE): https://c9x.me/compile/ (Quentin Carbonneaux's QBE compiler backend). Blog (active 2024–2025): https://harelang.org/blog/ Author: Drew DeVault and contributors (Sebastian, Pasta, spxtr, others). BDFL governance. §2 Architecture The Hare pipeline is one of the simplest in modern language design: Lexer/parser produce an AST. The type checker resolves a static, inferred type system with tagged unions and no generics. The compiler lowers...

Zig Self-Hosted Compiler

§1 Provenance Project home: https://ziglang.org/ Source: https://github.com/ziglang/zig Devlog (primary status source): https://ziglang.org/devlog/2025/ Self-hosted milestone post by Loris Cro: https://kristoff.it/blog/zig-self-hosted-now-what/ Self-hosted x86_64 default-in-debug announcement: https://ziggit.dev/t/self-hosted-x86-backend-is-now-default-in-debug-mode/10447 Mitchell Hashimoto on real-world build-time wins in 0.15.1: https://mitchellh.com/writing/zig-builds-getting-faster Lead author: Andrew Kelley, with a substantial contributor community (Jakub Konka on linkers, Matthew Lugg on incremental, etc.). BDFL governance via the Zig Software Foundation. §2 Architecture The Zig compiler pipeline is: Tokenizer and parser produce a...

.NET NativeAOT

§1 Provenance Official overview: https://learn.microsoft.com/dotnet/core/deploying/native-aot/ ASP.NET Core integration: https://learn.microsoft.com/aspnet/core/fundamentals/native-aot Source: the runtime/ILC compiler lives in https://github.com/dotnet/runtime under src/coreclr/tools/aot/ . Lineage: CoreRT (research project, 2014–2020, archived at https://github.com/dotnet/corert ) was renamed and rebooted as NativeAOT, shipped GA in .NET 7 (Nov 2022), expanded in .NET 8 (Nov 2023), .NET 9 (Nov 2024), and .NET 10 (Nov 2025). Authors: the .NET runtime team at Microsoft (Jan Kotas, Michal Strehovský, et al.). Key...

Crystal

§1 Provenance Project home: https://crystal-lang.org/ Source: https://github.com/crystal-lang/crystal Release blog: https://crystal-lang.org/blog/ (1.15.0 in Jan 2025, 1.16.0 in Apr 2025, 1.17.0 in Jul 2025, 1.18.0 in Oct 2025). Reference manual: https://crystal-lang.org/reference/ Author: Ary Borenszweig, Juan Wajnerman, Brian Cardiff at Manas Technology Solutions. Community-led since 2021 with 84codes sponsoring multi-threading work. Wikipedia overview: https://en.wikipedia.org/wiki/Crystal_(programming_language) §2 Architecture Crystal is a whole-program AOT compiler. The pipeline: Parser builds an AST. Semantic phases run macro expansion,...

GraalVM Native Image

§1 Provenance Project home: https://www.graalvm.org/ (Native Image reference manual at https://www.graalvm.org/latest/reference-manual/native-image/) . Source repository: https://github.com/oracle/graal (the Native Image / SubstrateVM tree lives at https://github.com/oracle/graal/tree/master/substratevm) . Foundational paper: Wuerthinger et al., "Initialize Once, Start Fast: Application Initialization at Build Time" (OOPSLA 2019). Earlier "One VM to Rule Them All" (Onward! 2013) describes the Truffle/Graal partial-evaluation pipeline that became the rest of GraalVM. Release calendar: https://www.graalvm.org/release-calendar/ . Current line in May 2026...

AOT Compilation Case Studies