auctex

The preview package for LaTeX allows for the processing of selected parts of a LaTeX input file. This package extracts indicated pieces from a source file (typically displayed equations, figures and graphics) and typesets with their base point at the (1in,1in) magic location, shipping out the individual pieces on separate pages without any page markup. You can produce either DVI or PDF files, and options exist that will set the page size separately for each page. In that manner, further processing (as with Ghostscript or dvipng) will be able to work in a single pass. The main purpose of this package is the extraction of certain environments (most notably displayed formulas) from LaTeX sources as graphics. This works with DVI files postprocessed by either Dvips and Ghostscript or dvipng, but it also works when you are using PDFTeX for generating PDF files (usually also postprocessed by Ghostscript). The tex-preview package is generated from the AUCTeX package for Emacs.