What are some alternatives?
When comparing IP Messenger and Feem, you can also consider the following products
LAN Messenger - LAN Messenger is a decentralized UDP IM-style chat client which supports usernames...
BeeBEEP - You can message and share files inside your intranet without a server.
Send Anywhere - Send whatever you want, wherever you want
KouChat - KouChat is a simple serverless chat client for local area networks (wifi).
Ruler - It's a screen ruler for Windows.
BORGChat - BORGChat is a LAN messaging software program.