LAN Messenger - LAN Messenger is a decentralized UDP IM-style chat client which supports usernames...
Freshservice - Freshservice: the one-stop cloud solution for all your IT management needs.
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.
Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community
MyChat - Secure instant messenger for any network
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.