Projects (.prj) that contain technical drawings or other CAD data can typically be opened and exported to one of the common CAD formats, including the exchange DXF format. This can be done in any program that supports this type of .prj files. May not always work, as there is many file types using prj file extension.
Convert Project file to AutoCAD DXF Drawing Exchange Format.
We found 3 software records in the database related to .prj to .dxf file format conversion.
Microsoft Windows software - convert prj to dxf on Windows
A widely-used 3D animation application from Autodesk
Convert from prj 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 prj to dxf. 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 graphics design tool for making 3D landscaping and animations
Apple macOS / Mac OS X software - convert prj to dxf on OS X
3D modeling and animation package for Mac.