To generate HTML documentation from sources contained in dox subdirectory, you need to have Tcl and Doxygen 1.8.5 (or above) installed on your system.
Use script gendoc (batch file on Windows, shell script on Linux / Mac OSX) located in adm directory to generate documentation.
To generate Overview documentation:
cmd> gendoc -overview
To generate Reference manual:
cmd> gendoc -refman
Run this command without arguments to get help on supported options.
See @ref occt_contribution__documentation for prerequisites and details on OCCT documentation system.