Enroot vs runhcs

Enroot is a free, open-source Linux command-line utility that turns traditional container and operating-system images into unprivileged sandboxes. It is aimed at high-performance or virtualized environments where portability and reproducibility matter and additional isolation is not required. Enroot runs without a daemon and supports unprivileged multi-user use without a setuid binary. Linux user and mount namespaces preserve filesystem separation, while the project provides little to no isolation. The command line covers batch, bundle, create, exec, export, import, list, remove, and start operations. It imports known formats including Docker, with the README reporting a 3x to 5x speedup for large Docker-image imports. Built-in GPU support uses libnvidia-container, and hooks can add NVIDIA support or Mellanox host MOFED. Runtime settings come from enroot.conf or higher-priority environment variables. Standard and hardened package flavors are available.

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