It looks like programs that can work with the ZARGO UML models (.zargo) should also possess the capability of exporting the diagrams as PDF documents for preview or print purposes. The preferred way for exporting diagrams however, is to pick a vector graphic or PostScript format.
Convert ArgoUML model file to Adobe Portable document format.
We have found 2 software records in our database eligible for .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