Apptainer vs Inclavare Containers

Apptainer is a free container platform for creating and running portable, reproducible workloads, with a focus on shared systems and high-performance computing. It packages containers as immutable, single-file Singularity Image Format (SIF) images designed for transport and sharing. By default, users retain the same privileges inside and outside containers. Images can be signed and verified with PGP keys, PEM keys or X.509 certificates, and encrypted containers can run without writing decrypted contents to disk. Apptainer imports containers from OCI registries and aims to support most Docker Hub containers without changes. It can expose host resources such as GPUs, high-speed networks and parallel filesystems, and supports NVIDIA CUDA, AMD ROCm, Intel Gaudi and OCI Container Device Interface accelerators. Running Apptainer requires Linux; Windows and macOS need a Linux virtual machine, with Windows also listed via WSL2. Root access is unnecessary when user namespaces are available. Full functionality requires kernel support for FUSE and unprivileged user namespaces. Community support includes Slack, Google Groups and GitHub, with commercial services through CIQ.

Inclavare Containers is a free, open-source Linux container runtime for launching protected containers in hardware-assisted Trusted Execution Environments. It creates hardware-enforced isolation between a tenant workload and privileged cloud-provider software. Its Enclave Attestation Architecture provides remote attestation that sensitive workloads run on trusted TEE hardware. The rune component is described as compliant with the OCI Runtime specification, while documented integrations include dockerd, containerd, and pouchd. Deployment can use Occlum LibOS or WebAssembly Micro Runtime, and Rats-TLS provides an attested secured channel between heterogeneous TEEs. shim-rune handles enclave signing and management between containerd and rune; epm manages cache pools for enclave startup. The project is cloud-platform agnostic and can run on public-cloud Kubernetes platforms. It supports Kubernetes CRI, uses the OCI image format, and documents Linux hosts including Ubuntu 18.04 and Alibaba Linux 2. Installation is described through source builds or RPM/DEB repositories.