FTL: A new operating system for clouds

# A new operating system for clouds Source: [https://ftl-os.org/](https://ftl-os.org/) ## What's FTL? - You canbuild 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, witha hypervisor\-like interfacebased on a lightweight hardware\-based isolation \(user mode\)\. You don't need bare\-metal machines\. - FTL iscompatible 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 tomake 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)