If you have a small network and needed to communicate without needed to use the internet or having to set up a communication server the following application is really great. It does not need an installation and can be run whenever needed. It works on port 2425 and automatically picks up other users on the network that are running the application that are part of the same subnet.
The good is that it has a log, quotes the last message in the reply, lets each member be part of a group and puts those people together. Additionally the really cool part is that it supports file transfer including folder transfer as well ....
Its freeware and maintains a small footprint about 5 MB of memory, peer to peer, scalable and almost never interferes with other applications.
The link for the site is below
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