---
title: "FTL: A new operating system for clouds"
slug: ftl-a-new-operating-system-for-clouds
url: https://listedarticles.com/articles/ftl-a-new-operating-system-for-clouds
canonical_url: https://ftl-os.org/
content_type: announcement
language: en
published_at: 2026-10-03T12:00:00.000Z
updated_at: 2026-10-03T17:11:22.814Z
author: "FTL"
authored_by: human
publisher: "FTL"
topics: ["open-source", "infrastructure", "systems-programming"]
license: all-rights-reserved
word_count: 304
reading_minutes: 1
citation: "FTL, FTL. \"FTL: A new operating system for clouds.\" 3 Oct 2026. https://ftl-os.org/ (all-rights-reserved)"
# The full text follows. The web page shows an extract and sends readers
# to the source above; quote the citation and link the canonical URL.
---

# FTL: A new operating system for clouds

> FTL introduces itself as a new operating system designed for clouds—outlining goals around cloud-native systems software and pointing to the project’s public materials.

## What's FTL?

  * You can build your own OS as a library. This userspace OS design makes it easy to add features, debug, upgrade the OS safely, as if writing applications.
  * FTL kernel isolates containers (userspace OS instances) better than existing monolithic kernels, with a hypervisor-like interface based on a lightweight hardware-based isolation (user mode). You don't need bare-metal machines.
  * FTL is compatible with Linux binaries. For example, the Rust-based HTTP server serving this website is a Linux application running on FTL. You can also run Unikernel-like specialized applications without POSIX abstractions.

## How it works

Each container runs a userspace OS. It is a shared library which implements most of OS concepts such as Linux process, VFS, and TCP/IP. FTL kernel provides a minimal interface to implement Linux system calls in userspace, just like a hypervisor.

FTL combines the best of microkernels (flexible & secure) and monolithic kernels (performant & simple). Our goal is to make lightweight containers as secure as VMs, and unlock new OS-level abilities in applications, without sacrificing performance:
    
    
    FTL                                   Linux
    ┌────────────────────────────────┐    ┌────────────────────────────────┐
    │┏━━━━━━━━━━━━━┓  ┏━━━━━━━━━━━━━┓│    │┏━━━━━━━━━━━━━┓  ┏━━━━━━━━━━━━━┓│
    │┃             ┃  ┃             ┃│    │┃             ┃  ┃             ┃│
    │┃    Linux    ┃  ┃    Linux    ┃│    │┃    Linux    ┃  ┃    Linux    ┃│
    │┃   Process   ┃  ┃   Process   ┃│    │┃   Process   ┃  ┃   Process   ┃│
    │┃             ┃  ┃             ┃│    │┃             ┃  ┃             ┃│
    │┃╌╌╌╌╌ Linux system calls ╌╌╌╌╌┃│    │┗━━━━━━━━━━━━━┛  ┗━━━━━━━━━━━━━┛│
    │┃                              ┃│    └────────────────────────────────┘
    │┃         Userspace OS         ┃│    ╌╌╌╌╌╌╌╌ **Linux's interface** ╌╌╌╌╌╌╌
    │┃   (Process, VFS, TCP, ...)   ┃│    ╔════════════════════════════════╗
    │┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛│    ║                                ║
    └────────────────────────────────┘    ║          Linux Kernel          ║
    ╌╌╌╌╌╌╌ **minimal interface** ╌╌╌╌╌╌╌╌    ║                                ║
    ╔════════════════════════════════╗    ║   process, fork/exec, memory,  ║
    ║           FTL Kernel           ║    ║     signals, TCP/IP, /proc,    ║
    ║    vCPU, memory, drivers, ...  ║    ║       /dev, drivers ...        ║
    ╚════════════════════════════════╝    ╚════════════════════════════════╝
    

Userspace OS design also enables you to extend most of Linux kernel features without kernel/eBPF programming. You can add printfs, apply security updates, and add new features quickly and safely. In FTL, OS is just a library. [Read more](https://seiya.me/blog/introducing-ftl).

## Roadmap

  * September 2026: Run a simple Linux HTTP server on FTL (released in [v0.0.1](https://seiya.me/blog/introducing-ftl) ✅)
  * October 2026: Async Rust apps support - Linux threads, epoll, ... (released in [v0.1.0](https://seiya.me/blog/ftl-v0.1.0) ✅)
  * November 2026: Filesystem
  * December 2026: Node.js / Go support
  * January 2027: SMP, container images, 64-bit Arm support

## Links

  * [GitHub repository](https://github.com/nuta/ftl)
  * [Introducing FTL: A new operating system for clouds (blog post)](https://seiya.me/blog/introducing-ftl)