Xpdf

Xpdf is a free PDF viewer for Unix -like operating systems, which has since been ported to Windows. Under Unix, Xpdf uses the Motif toolkit under the X server. On Windows, by default, only the parts of the program run that do not require X server support (like pdftops and pdftotext ).

In addition to a pure display program provides Xpdf prepared other programs that allow to convert PDF files to read PDF information or to extract embedded images in the PDF document.

Criticism

Lately Xpdf is increasingly coming under criticism. On the one hand, the closed development approach has been criticized, which prevents other developers to easily contribute code, as with many other free software projects usual. Also provides Xpdf any libraries available against which can be linked. Programs that wish to use Xpdf must, partly to place code of Xpdf. This has the consequence that vulnerabilities in the code of Xpdf require not only an update of Xpdf, but also of all programs that contain Xpdf. Controversial is also the attempt with as few dependencies on other programs equip Xpdf as possible. Many developers complain that this is not always advantageous.

In response to these criticisms, the project was founded in Poppler, a fork of Xpdf, which is being developed for a new model in which the critical points are eliminated.