Our system adopts network boot system. Because of how the system is set up, it is not possible to have the latest version of software all the time, but we are striving to have the most updated software possible, within a few days to within a month time period as a rule. As for major version upgrades (2.x to 3.0 for instance), we do not necessarily do it, considering the repercussions and other matters that it might cause to the users.