TeXworks is an open-source application software, available for Windows, Linux and OS X. It is a Qt-based graphical user interface to the typesetting system TeX and its extensions LaTeX, ConTeXt, and XeTeX. TeXworks is targeted at the direct generation of PDF output. It has a built-in PDF viewer using the poppler library; the viewer has auto-refresh capability and also features SyncTeX support (which allows the user to synchronize the PDF viewer position with the source and vice versa with a single click).