UMLGraph - UMLGraph is a professional automated drawing tool that allows the designers the declarative specification and drawing of UML class and sequence diagram.
Omegle - Omegle is one of the most popular online chat website allowing user to communicate with anyone without registration.
Dia - Dia is a GTK+ based diagram creation program for GNU/Linux, MacOS X, Unix, and Windows, and is released under the GPL license.
Bazoocam - Bazoocam is a popular chat website that rapidly connects you with strangers to chat.
yEd - yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.
Chatrandom - Chatrandom provides medium to users for having chat at random with different users around the globe.