Latex is one of the best environment to make or edit scientific papers or documents. Its powerful language allows to build expressions or mathematical formula by building a simple text file. Often mathematical expressions populate also the images of scientific documents and a typical instrument to insert easily Latex expression on vectorial .eps images is psfrag. Using Inkscape for Linux, is also possible to insert Latex formula as an image on a picture. This option is available in the Inkscape v. 0.48 witch includes in the menu
Effects -> Render -> Latex Formula
The option is available by downloading the latex package for ubuntu just typing:
sudo apt-get install texlive pstoedit
and successively open the Inkscape application.