Cytosim understands these file extensions:

Extension	Type	Typical usage
`*.cym`	input	configuration file
`*.cms`	input	configuration file for `play` containing display parameters
`*.cmo`	output	files generated by `sim`

sim usually produces 3 output files:

File	Type	Content
`properties.cmo`	text	properties of the objects
`objects.cmo`	binary	positions of the objects at different time points
`messages.cmo`	text	information such as the execution time

objects.cmo is called the trajectory file.

play reads:

properties.cmo
objects.cmo

'play live' reads the configuration file (by default config.cym) and usually does not write any file, but the user can save images or export simulation snapshot (a trajectory file containing only one time point). See menu -> export.