shellin

Shellin is an embeddable shell runtime and scripting language designed to provide secure, scriptable command execution for resource-constrained environments such as embedded systems and Internet of Things devices. It emphasizes a small footprint, deterministic behavior, and a minimal dependency surface to enable reliable operation in remote or low-power hardware.

The project began as an open-source effort led by the NovaCore Collective and was released in 2023 as part of the EdgeStack ecosystem. It is maintained by a community of contributors with periodic major releases and long-term support for stable deployments.

Shellin is implemented in Rust to prioritize memory safety and performance. It exposes a POSIX-like command interface, supports scripting with a concise language, and runs commands in a sandboxed environment. Security features include sandbox isolation, capability-based permissions, and optional syscall filtering. The runtime is designed to be modular, allowing extensions through plugins and external modules, and aims to stay portable across Linux, Windows, and other Unix-like systems.

Common use cases include automating maintenance tasks on edge devices, providing a restricted administrative shell inside containers or gateways, and serving as a lightweight command execution layer for OTA updates and device management.

Reception has been mixed. Proponents praise its security model and compact footprint, while critics note a smaller ecosystem and learning curve for users accustomed to traditional shells. The project emphasizes compatibility with standard shell syntax while offering enhanced isolation features.

See also: Shell, Sh, BusyBox, Rust programming language, Seccomp.