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Lwt module type definitions for MirageOS applications








MirageOS is a library operating system that constructs unikernels for secure,
high-performance network applications across a variety of cloud computing and
mobile platforms. Code can be developed on a traditional OS such as Linux or
MacOS X, and then compiled into a fully-standalone, specialised unikernel that
runs under the Xen or KVM hypervisors as well as lightweight hypervisors like
FreeBSD's BHyve, OpenBSD's VMM. Xen and KVM power many public clouds;
MirageOS unikernels are currently running on Amazon's Elastic Compute Cloud
and Google Compute Engine, and maybe others!

The most up-to-date documentation can be found at the
homepage. The site is a Xen hosted unikernel.
Simpler skeleton applications are also
available online.

This repository

This repository includes:

  • a command-line tool to create and deploy applications with MirageOS; and

  • in types/, a library of type signatures that compliant applications use.

There are several diverse backends in MirageOS that require rather specialised
build steps (from Xen to KVM unikernels), and this complexity is wrapped
up in the tool.

To work with mirage, you'll need to either install prerequisites
locally or use the Docker image.

Local install

You will need the following:

  • a working OCaml compiler (4.04.2 or higher).

  • the OPAM source package manager (2.0.0 or higher).

  • an x86_64 or armel Linux host to compile Xen kernels, or FreeBSD, OpenBSD or
    MacOS X for the solo5 and userlevel versions.

Docker image

There is a maintained Docker image at
You can also use the Dockerfile in this repository:

docker build -t mirage .
docker run -v <your-source>:/src opam config exec -- mirage

Using mirage

There are two stages to using mirage:

  • a configure phase where necessary code is generated and dependencies are determined.

  • an optional depends phase where OPAM package dependencies are satisfied.

  • a build phase where the compiler and any support scripts are run.

You can find documentation, walkthroughs and tutorials over on the
MirageOS website.
The install instructions
are a good place to begin!