Chat application with administrative features, simple analog of ICQ (Skype or Viber):
-Multithreading client/server application;
-"Waiting" connection in separate thread allows to notify client's part immediately when data changed on server. ("Comet" technology, but without 3-rd party components);
-Allows one to one and group chats
-Remote shell command may be executed for specific client;
-Update module (new versions may be installed by one admin's click);
-Ban / unban users, delete users from chat;
-Resends unsent messages due connection problems when connection restored;
-Offline messages history.


Technologies: C#, Windows Forms, Windows Service, MS SQL, Linq, TCP/IP, Sockets.