Cordium is a FOSS, self-hosted, identity-based, general-purpose sandbox platform that I've been working on for a long time now that is built on Kubernetes and Octelium, my main project. The key differentiator here for Cordium, when compared to other dev environments (e.g. GitHub Codespaces) and sandbox platforms (e.g. E2B, Daytona, etc.), is that Cordium automatically provides identity-based, secretless secure access to resources/infrastructure (e.g. APIs, SSH, databases, k8s, etc.) without having to inject credentials (e.g. API keys, SSH private keys, database passwords, etc.) into the sandbox where the upstream credential is held by the identity-aware proxy of the Octelium-protected resource outside the reach of the sandbox.

In short, Cordium is not just an isolated execution environment that can replace remote development environments and sandbox platforms, but also equally a secure access platform to infrastructure/resources. It's basically a sandbox platform + a ZTNA/remote-access-VPN baked-in with unified identity management, L7-aware access control and visibility.