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.
Gas Mask - Gas Mask is simple hosts file manager for Mac OS X.
MyChat - Secure instant messenger for any network
SwitchHosts - Free and open source hosts management & switching app
BORGChat - BORGChat is a LAN messaging software program.
BlueLife Hosts Editor - BlueLifeHosts editor is a Portable freeware application for editing windows Hosts file ,(easily add/delete , Block , Update domain names)