A software management system provides a software management device which manages a plurality of software programs installed in a plurality of managed devices in connection with a plurality of software-updating module delivery devices. The software management device receives adaptive version data from the managed device and current version data from the software-updating module delivery device. When the current version of software, indicated by current version data, is later than the adaptive version of software, indicated by adaptive version data, the software management device downloads software-updating modules from the software-updating module delivery device, thus updating the adaptive version of software installed in the managed device by use of software-updating modules.