Ipe extensible drawing editor is a very nice tool for drawing figures for LaTeX. It is developed by Otfried Cheong. The source code and the binaries for Windows and Linux can be downloaded from ipe.compgeom.org.
The features of ipe are (from the web site):
* Entry of text as LaTeX source code. This makes it easy to enter mathematical expressions, and to reuse the LaTeX-macros of the main document. In the display text is displayed as it will appear in the figure.
* Produces pure Postscript/PDF, including the text. Ipe converts the LaTeX-source to PDF or Postscript when the file is saved.
* It is easy to align objects with respect to each other (for instance, to place a point on the intersection of two lines, or to draw a circle through three given points) using various snapping modes.
* Users can provide Ipelets (Ipe plug-ins) to add functionality to Ipe. This way, Ipe can be extended for each task at hand.
* The text model is based on Unicode, and has been tested with Korean, Chinese, and Japanese.
* The UI is implemented using the portable toolkit Qt, and so can be compiled for Unix, Windows, and Mac OS X (see below).
It can save its figures in the EPS (encapsulated Postscript) format for using with dvips or in the PDF format for using with pdflatex.
Ipe is not very simple to use since it has some special tricks (for example the transition between different modes can be cumbersome sometime), but it is very powerful for drawing even complex figures for LaTeX and it is now my main drawing software.
