Upstream tarball ---------------- Upstream distributes SML/NJ as a collection of tarballs. The Debian orig tarball contains all of them, unpacked where the upstream config/install.sh script expects them, plus the upstream boot images (bootstrap/boot.*-unix.tgz, unpacked) for the architectures Debian builds for. The boot images are used only to build a bootstrap compiler, which then recompiles the whole system from source; the boot images shipped in the binary packages are the freshly built ones. The debian/mkorig script assembles the tarball, and is hooked into debian/watch, so "uscan" does the whole job. It can also be run by hand: debian/mkorig --upstream-version 110.99.9 Debian follows the 110.99.x "legacy" series of SML/NJ, which upstream recommends for production use. The 20xx.y releases are a new development series with an LLVM-based code generator (using a customized bundled LLVM) that only supports amd64 and arm64. Architectures ------------- As of 110.99, SML/NJ has a native amd64 (64-bit) code generator, and the amd64 package is built with it. Earlier Debian packages for amd64 contained 32-bit x86 binaries. -- Barak A. Pearlmutter , Sat, 12 Sep 2026