papaw vs Sentinel Envelope

papaw is a Linux executable packer for programs that include statically linked third-party components, aimed at devices with limited disk space. It compresses executables and bundles them with a decompressor of about 15–40 KB. Supported algorithms are LZMA2, LZMA1, Zstandard and Deflate, and packed executables can replace themselves on disk when run. The project is free and unencumbered software under the MIT license, and can be self-hosted. It uses Meson and can be included as a Meson subproject; the README recommends `custom_target()` for running `papawify`. Prebuilt static binaries are available through GitHub releases, with example assets for aarch64, arm, armeb, i386, mips, mipsel and x86_64. To support portability, the project avoids machine-specific assembly and newer system calls such as `fexecve()`. Optional very basic anti-debugging protection is intended to discourage trivial reverse-engineering techniques. The payload is extracted to a temporary file; when run as root, papaw mounts a tmpfs filesystem and lazily unmounts it before extraction.

Sentinel Envelope has no write-up on Specifiction yet; its figures are above.