telegram for desktop
Popular
Free   
19

Enjoy even more Telegram in your PC now; easier and with a lot of functions.

webogram
Popular

Webogram

 Alpha
Free (Open Source)   
11

A non-official web slient for Telegram; one of the best apps of the time.

line

Line

 5.22.0.2111
Free   
24

Line, now available for your PC.

mirc

mIRC

 7.73
Trial   
42

A complete IRC client with a lot of features than the other cannot have.

clicksandwhistles
Free (Open Source)   

This is a messaging application that offers you a large amount of new features.

retroshare

RetroShare

 0.5.1
Free (Open Source)   

Instant messaging in an open source

coccinella

Coccinella

 0.96.20
Free (Open Source)   

This is a program with attractive options extras for chatters.

icq

ICQ

 22.11.1.47633
Free   
7

Here is a fantastic instant messenger tool that will allow you to chat with multiple users.

xchat

XChat

 2.8.6-2
Free (Open Source)   

This is a IRC customer for having a chat on Internet or in a local network