What is the equivalent of the 'gsettings' command on OS X?
The most approaching command line interface on MacOS X is the command defaults. All the settings are hierarchically structured inside domains, which are separated by dots (as in Ubuntu settings).

To get all the domains containing settings (the equivalent of gsettings list-schemas), enter:

defaults domains


and for a human readable version, enter:

defaults domains | sed -E 's/, /\
/g' | sort