Prince is a computer program that converts XML and HTML documents into PDF files by applying Cascading Style Sheets. Prince is a commercial product, which is free to download and use for non-commercial purposes. Prince supports all common web standards, including HTML, CSS and JavaScript, through its own code. That is, Prince is not based on a browser engine, but implements its own engine in the Mercury programming language. Prince can generate accessible PDFs conforming to the PDF/UA profile that can be used by people with assistive technologies. Prince supports many languages, including Thai, Indic scripts and right-to-left scripts like Arabic and Hebrew. Prince is developed by YesLogic, a small company based in Melbourne, Australia. Since 2004, Håkon Wium Lie, the co-creator of CSS, has been chairman of the board.
History
In April 2003, Prince 1.0 was released, with basic support for XHTML, Cascading Style Sheets, Scalable Vector Graphics, and arbitrary XML. This first version was a command-line program that supported Microsoft Windows and Linux; there was no graphical user interface for Windows yet. In December 2005, Prince 5.1 passed the Acid2 test from the Web Standards Project. It was the third user agent to pass the test, after Safari and Konqueror. In June 2012, Prince 8.1 added support for . In subsequent releases, CSS support has steadily been extended, both to have comparable support with web browsers, and to add support for print-specific features, like page breaks and footnotes. Prince is available for several plaforms, including Windows, Linux, macOS, FreeBSD, and Solaris. Wrappers are available for Java SE,.NET Framework, ActiveX, PHP, Ruby on Rails and Node.js to help integrate Prince into websites and apps.
Prince was developed using the Mercuryfunctional logic programming language. The main driving force behind Prince is the standard CSS3-paged that integrates paged media layout specification with any other W3C technologies: HTML4, HTML5, XHTML, and "free XML", working or not with JavaScript. Prince has good support for CSS with proprietary extensions for print-related functionality not currently in the CSS standard. Prince supports most of ECMAScript 5th edition, but not strict mode. Later editions of ECMAScript are not supported.
