xfig

xfig is a menu-driven tool that allows the user to draw and manipulate objects interactively under the X Window System.

To start xfig, enter the command: xfig
or to open a file in xfig: xfig filename

A reference guide for xfig is available here.
Online help is also available under the "Help" menu in the xfig window.

Click here to find out how to add LaTeX to figures in xfig.