: Papers detail the use of TCP for reliable, two-way messaging and UDP for lightweight broadcasting or client discovery. Popular Free LAN Chat Software

Popular for office environments; supports remote desktop and group rooms (Free trial/version often available). Microsoft Store Key Research Resources

A free, open-source LAN messenger that is easy to deploy without complex configuration. GitHub

If you are looking to download and study existing implementations, several free and open-source options are widely cited:

: Most systems utilize either a Client-Server model, where a central server handles message broadcasting, or a Server-less (P2P) model for direct communication.