One codebase. The same public API on every target Jam can configure.
Desktop Windows with the Visual C++ toolset. MinGW is available.
Desktop and embedded Linux on common CPU families, using GCC or Clang.
macOS with the compilers from Xcode.
Cross-compiled with Emscripten for browsers and wasm runtimes. Set TARGET_OS to emscripten when configuring.
QNX Neutrino with the QCC compiler.
AIX and Solaris with the system compilers or GCC.