WiX Files
All input files and intermediate files for WiX are xml files. Output is in the form of standard Windows Installer database files.
Source files (.wxs and .wxi) are compiled, producing object files (.wixobj). These objects files are then consumed by the linker which produces Windows Installer database files (.msi or .msm). This is analogous to the C++ model of compiling source code to object files, then linking to produce executables.
Input Files Intermediate Files Output Files