LaTeX (pronounced LAH-tek or LAY-tek) is a free. document creation system that offers high-quality typesetting. It is heavily used in mathematics, the sciences, and in engineering publications,including some dissertations and books. A number of scholarly journals require that articles for publication be created in LaTeX.
LaTeX allows the author to focus on content, rather than layout. LaTeX takes a "plain text" document and converts it into a high-quality document that can be printed or posted online.
Developed in the 1980s by Leslie Lamport at SRI International, LaTeX is based on the TeX markup language. TeX was created by Donald Knuth, originally for his seminal work: The Art of Computer Programming. LaTeX documents will have the .tex file extension.