It looks like programs that can work with the ZARGO UML models should also possess the capability of exporting the diagrams as PDFs. The preferred way for exporting diagrams however is to a vector graphic or PostScript.
Convert ArgoUML model file to Adobe Portable document format.
We found 2 software records in the database related to .zargo to .pdf file format conversion.
Microsoft Windows software - convert zargo to pdf on Windows
A UML modeling tool
Convert from zargo file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned zargo to pdf. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
A program for modelling in UML language