The code is structured into these files: virt_top_utils.mli / virt_top_utils.ml String functions and other small utility functions. This is included directly into virt_top.ml. virt_top.mli / virt_top.ml This is the virt-top program. The two interesting functions are called 'collect' and 'redraw'. 'collect' collects all the information about domains, etc. 'redraw' updates the display on each frame. Another interesting function is 'start_up' which handles all start-up stuff, eg. command line arguments, connecting to the hypervisor, enabling curses. The function 'main_loop' runs the main loop and has sub-functions to deal with keypresses, help screens and so on. virt_top_xml.ml Any code which needs the optional xml-light library goes in here. Mainly for parsing domain XML descriptions to get the list of block devices and network interfaces. The reason for having it in a separate file is so that we don't depend on xml-light. virt_top_csv.ml Any code which needs the optional ocaml-csv library goes in here. This implements the --csv command line option. virt_top_calendar.ml Any code which needs the optional ocaml-calendar library goes in here. This implements the --end-time command line option. virt_top_main.ml This is just a small bit of code to glue the modules together Virt_top + Virt_top_xml? + Virt_top_csv? + Virt_top_calendar? The man-page is generated from the single file: virt-top.pod which generates (using perldoc) the following: virt-top.1 virt-top.txt