# Xenolith SDK

> A cross-platform C/C++ SDK: a Vulkan graphics engine, a self-contained system
> runtime (umbrella libc + freestanding sprt/cxx + a full LLVM libc++ port in
> std::__sprt), and a full set of application libraries. Build for Linux, Windows,
> Android and macOS from one codebase — without the Windows SDK, the Android NDK
> or the macOS SDK (`+sprt` variant). The toolchain ships everything it needs,
> including GNU Make, the bundled xlmake driver, Clang 22.1.8 and linkers.

Public contact: Dmitry Mukanin <dmitry@xenolith.studio>.
Lead developer: Roman Katuntsev.
License: see the repository.

## What it is

- **No platform SDKs.** Windows builds without UCRT or the Windows SDK, Android without the NDK, macOS without the macOS SDK via `+sprt`. This removes the related technical and licensing barriers.
- **One API.** As far as technically possible, every platform exposes the same interface — no forests of `#ifdef`, no per-OS rewrites.
- **One build.** Every build is a cross-compile; switch target with a single flag (`STAPPLER_TARGET=<triple>`). Same source, same Makefile.
- **Reproducible.** The toolchain pins exact versions of GNU Make, xlmake, Clang/LLVM 22.1.8, lld, lldb and the shader compiler.

## Platform support

- Linux: x86_64, arm64, riscv64 — glibc and musl
- Windows: x86_64, arm64 — custom libc, no UCRT or Windows SDK
- macOS: x86_64, arm64 — including builds with the Xenolith Runtime (`+sprt`)
- Android: all ABIs (arm64, armv7, x86, x86_64) — with and without the NDK
- iOS: arm64 + simulator — in development (toolchain sysroot only)

## System runtime (SPRT)

- One POSIX surface across glibc, musl, Bionic and macOS; a fully custom libc on Windows (mimalloc allocator, no UCRT).
- Full pthread with priority-inheritance mutexes (futex on Linux, WaitOnAddress on Windows, os_sync on macOS), robust mutexes, a writer-fair rwlock.
- `longjmp` that unwinds the C++ stack so destructors run.
- Two C++ libraries: freestanding `sprt/cxx` (exception-free, `Status`/`Result<T>`) and a full LLVM libc++ port in `std::__sprt` for application code.
- Unified event loop (Looper/Queue) over epoll + io_uring, IOCP, kqueue/CFRunLoop, ALooper.

## Graphics engine (Vulkan)

- Render graph with automatic barriers and layout transitions; graphics and compute in one graph.
- On-demand rendering — a frame is prepared only when the scene changes.
- CPU software backend — the same scene graph rasterizes without a GPU.
- GPU glyph atlas, variable fonts, FreeType + HarfBuzz typography.
- ~4000 vector Material icons, crisp at any density.
- Flexbox and CSS grid UI toolkit, Material Design 3, Rich Text, HTML/EPUB rendering, gesture recognition, animation with ~30 easing curves.
- MoltenVK on macOS with the correct portability subset.

## Application libraries (Stappler)

- Object database over PostgreSQL and SQLite: declarative schemes, role-based access control, full-text search in 23 languages.
- `Value` container serializing to JSON, CBOR or a URL-safe format with LZ4 compression.
- Cryptography: OpenSSL / GnuTLS / mbedTLS; RSA, ECDSA, EdDSA; GOST 3410/3411/3412 (OpenSSL & GnuTLS); JWT.
- Arena memory pools or plain malloc — a single template parameter, no code changes.

## Experimental / on the roadmap (not shipping as stable)

- Remote rendering: thin-client / GPU-server over QUIC; scene-graph serialization exists, the streaming per-frame protocol is still ahead.
- WebAssembly plugins (WAMR host); graphics not yet exposed to guest code.
- GPU particle systems and iOS are in active development.

## Links

- Source & docs: https://github.com/XenolithEngine/xenolith-engine
- Installer (one-click GUI + headless CLI): https://github.com/XenolithEngine/xenolith-installer
- Website: https://engine.xenolith.studio/ (en) · https://engine.xenolith.studio/ru/ (ru) · https://engine.xenolith.studio/zh/ (zh)
- Contact: dmitry@xenolith.studio