C

• NinePea - Library for implementing 9p resources on Arduino
• pi9 - 9p2000 server library
• Plan9 9p(2) - 9front's 9p(2)
• Plan9Port 9p(2) - Plan9Port's 9p(2)
• Plan9Port 9pclient(2) - Plan9Port's 9pclient(2)
• c9 - 9p2000 client and server library
• libixp - 9p2000 client and server library based on Plan9's 9p(2)

C#

• Sharp9P - 9p2000 library

Go

• styx - Droyo's library focusing on 9p2000 servers
• go-p9p - Docker's performant 9p2000 library
• go9p - 9P2000 implementation in Go
• ninep - Package for implementing 9p2000 clients and servers
• go-p9p - Docker's performant 9p2000 library

Haskell

• network-ninep - 9p2000

Python

• space9 - Simple 9p2000 library

Rust

• rust-9p - Rust library for 9p2000.L
• rs9p - Rust crate for 9p2000.L

Scheme

• chicken-9p - CHICKEN Scheme library for 9p2000

Ruby

• r9p (deprecated) - 9p2000 client implementation for Ruby

Lua

• libstyx2 - C/Lua 9p2000 library based on libstyx

Go

• jobd - Cron as a file system
• ghfs - Represent GitHub as a file system

Plan9

• hammer2fs - Implementation of the hammer2 filesystem
• archfs - Mount mkfs(8)-style archive
• bzfs - Bunzip2 archives
• cdfs - CD (.iso)
• cifs - Mount Microsoft™ SMB/CIFS shares
• consolefs - Serial console access
• factotum - Authentication agent (key storage)

Learning

• jsonfs - JSON as a fs
• semfs - Semaphores as a fs by Nemo
• asemfs - Semaphores as a fs by Nemo with authentication support
• simplefs - Demonstrative fs that's a reduction of the framework shown in semfs by Nemo
• bankfs - Demonstrative fs which features gross abuse of the [9pfile(2)](http://man.cat-v.org/9front/2/9pfile) library
• ramfs (lib9p) - Not to be confused with ramfs(4)

Windows

• ninefs - A 9p file system for windows using dokan

C

• dawfs - A DAW as a file system

C

• 9mount - Mount 9p filesystems (no FUSE)
• 9pfuse - Mount 9p file systems through FUSE
• 9p(1) - Plan9Port's 9p(1) command for interacting with 9p file systems

• 9p2000 RFC (wip) - WIP drafting of a 9p2000 (and friends) RFC document
• 9p2000.u RFC (wip) - WIP drafting of a 9p2000.u RFC document
• Writing a 9p server from scratch - Three post series on implementing 9p file servers in Go
• Linux's v9fs docs - 9p2000.L documentation
• The Styx Architecture for Distributed Systems
• Cron as a file system

Manuals

• intro(4) - Introduction to writing file servers in Plan9Port
• 9pclient(3) - The 9pclient library helps client programs interact with 9P servers
• post9pservice(3) - Library for posting 9p services for client consumption
• intro(5) - Introduction to the Plan 9 File Protocol, 9P

Python

• 9p2000.L - 9p2000.L Linux kernel module