It runs on Unix-like systems including Mac OS X and Linux with the Qt libraries installed. LaTeX is most widely used by mathematicians, scientists, engineers, philosophers, linguists, economists and other scholars in academia. As a primary or intermediate format, e. g. , translating DocBook and other XML-based formats to PDF, LaTeX is used because of the high quality of typesetting achievable by TeX. Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The typesetting system offers programmable desktop publishing features and extensive facilities for automating most aspects of typesetting and desktop publishing, including numbering and cross-referencing, tables and figures, page layout and bibliographies. Kile is a TeX/LaTeX editor to edit TeX/LaTeX source code.