I recently realized that the "X" in "OS X" represents the Roman numeral for 10, which is probably pretty obvious for most of you. But this got me thinking. That means that in four years, assuming Apple maintains the usual annual iOS release schedule, iOS will reach its tenth version in four years. Furthermore, Apple is most likely to call it iOS X. Additionally, (Mac) OS X has traditionally kept a biannual release schedule, except for this year. If they continue the biannual release schedule, Mac OS 10.9 will release in 2014. Apple will be able to milk that out for two years, which would give Mac OS 11 (or XI) the release year of 2016, the same year as the release of iOS X. However, I estimate that Mac OS XI will never exist, as it will be replaced by iOS X. This also explains why Apple dropped the "Mac" from "Mac OS X", so there would be an easier name transition from OS X to iOS X. Of course, if Apple does release Mac OS 10.9 next year (2013), then my prediction is almost certainly incorrect, but please let me know what you think of this!