Open Source PDF Software

wkhtmltopdf and wkhtmltoimage are open source (LGPLv3) command line tools to render HTML into PDF and various image formats using the Qt WebKit rendering engine. These run entirely "headless" and do not require a display or display service. There is also a C library, if you're into that kind of thing. The file pdf.h contains a fairly high level and stable pure c binding to wkhtmltopdf. These binding are well documented and do not depend on QT. Using this is the recommended way of interfacing with the PDF portion of libwkhtmltox. The rest of the headers directly exposes the C++ QT dependent class used internally by wkhtmltopdf and wkhtmltoimage. wkhtmltopdf is able to put several objects into the output file, an object is either a single webpage, a cover webpage or a table of contents. The objects are put into the output document in the order they are specified on the command line, options can be specified on a per object basis or in the global options area.

dompdf is an HTML to PDF converter. At its heart, dompdf is (mostly) a CSS 2.1 compliant HTML layout and rendering engine written in PHP. It is a style-driven renderer, it will download and read external stylesheets, inline style tags, and the style attributes of individual HTML elements. It also supports most presentational HTML attributes. PDF rendering is currently provided either by PDFLib or by a bundled version the R&OS CPDF class written by Wayne Munro. (Some important changes have been made to the R&OS class, however). In order to use PDFLib with dompdf, the PDFLib PECL extension is required. Using PDFLib improves performance and reduces the memory requirements of dompdf somewhat, while the R&OS CPDF class, though slightly slower, eliminates any dependencies on external PDF libraries.