XGL 3D CAD models (.xgl) can be converted to all kinds of other 3D modeling formats, including IGES format (.igs, .iges). You will have to either use some of the 3D modeling tool with XGL and IGES support, or some dedicated 3D model converter.
Convert XGL 3D CAD model to IGES 3D exchange format.
We found 2 software records in the database related to .xgl to .igs file format conversion.
Microsoft Windows software - convert xgl to igs on Windows
A 3D CAD translation softwate
Convert from xgl 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 xgl to igs. 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 CAD viewer program with conversion capabilities