GanttProject - HTML/PDF

Ganttproject can also export the project as HTML web pages. The different web pages contain all the information about the project: For HTML export GanttProject uses the XSL stylesheet to HTML transformation.
GanttProject uses by default the XSL stylesheet included in the jar file.
But you can specify another xsl stylesheet by selecting the directory containing it on the setting dialog.
In fact you can create your own xsl stylesheet files to customize your html web pages.

For PDF export the software uses the FOP library to export in pdf format. It also use the xsl transformation technology.
So you can use PDF themes, and a default theme included in the GanttProject jar file.