Cyphera Runtime
The Rust POSIX / libc compatibility layer for CypheraOS. Cyphera Runtime is the userland boundary — the layer that lets standard C and POSIX-oriented software run on the Cyphera Kernel without a traditional C libc.
What it is
Modern operating systems are not just kernels. The kernel is the privileged half; the userland boundary — libc, the syscall ABI, POSIX expectations, dynamic linking, threads, signals — is the half that actually decides whether existing software can run. A memory-safe kernel without a memory-safe runtime sitting above it still leaves the practical attack surface intact.
Cyphera Runtime is that runtime layer, built in Rust. It is the compatibility surface real workloads land on when they execute against the Cyphera Kernel.
Current work
- cyphera-libc — the Rust libc and POSIX-compatibility surface that lets standard C/POSIX software run on the Cyphera Kernel without a traditional C libc. Focused on the userland surface real workloads on CypheraOS actually exercise.
- Userland compatibility experiments — busybox-static and standard developer tools today; broader Rust-userland (uutils-style) a future direction.
- Syscall boundary work — coverage of the Linux ABI surface that real software actually depends on, identified by running real workloads rather than counting headers.
Status
Cyphera Runtime is active research. It is not currently positioned as a drop-in libc replacement for general-purpose use. The focus is supporting the real workloads CypheraOS needs to run — Cyphera Platform services, demonstration apps, and the kinds of C/POSIX-oriented software security customers actually deploy.
Real software validated through the runtime so far includes standard C utilities and developer tools. Progress is measured by workload coverage, not synthetic conformance.
How it fits the Cyphera platform
Cyphera Runtime sits between the Cyphera Kernel and the rest of the world. Above it, the Cyphera Platform services (KMIP server, PKI server, Secrets Manager) and any customer workload can run with a memory-safe userland boundary. Below it, the Cyphera Kernel provides the privileged side of the same picture.
Together, Cyphera Kernel + Cyphera Runtime + CypheraOS packaging is what makes "Rust all the way down" a deployable picture rather than a slogan.
Release model
Cyphera uses a mixed release model. Selected components are released as open source under permissive licenses, including the FPE SDKs and reference implementations. Cyphera Runtime — both the integration work and the cyphera-libc effort — may be released as packaged images, source under the same mixed licensing as the rest of CypheraOS, or controlled pilots depending on maturity. Source publication decisions will be made component-by-component as the work matures.
Working with us
Cyphera Runtime is developed by Horizon Digital Engineering LLC. We are interested in research partners, pilot users, and non-dilutive funding opportunities in trusted computing, secure runtime infrastructure, embedded systems, and defense software modernization.
For evaluation access, collaboration, or technical discussion, reach out via contact.