Softros LAN messenger - LAN messenger for an internal office chat for home or business users. It does not require a server and is very easy to install and use. It supports personal chats, group chats, message brodcasting, files transfer and remote desktop access.

Phonebot - Make phone calls from within a Slack channel

MyChat - Secure instant messenger for any network

ShareAccount - Share your account without giving out your password

BORGChat - BORGChat is a LAN messaging software program.

Wing-project.org - WING - Wireless Mesh Network for Next-Generation Internet