In this article, we deal with software radio in an original manner and we insist on the fact that software radio is a major evolution of radio technologies and a convergence of different pre-existing fields. Joe Mitola deserves credit for formalizing and conceptualizing this evolution. We will not define software radio. We will rather look at software radio from different perspectives. The new equipments include more and more software radio "capacities", i.e. they can be reconfigured thanks to software. Certain former analog functionalities are now performed digitally. We think that the time frame, during which software radio is advantageous, compared with a velcro approach for multi-standards terminals, is probably over. However, software radio has taken concrete form in the military field. We will show that software radio is used de facto in all the equipments and products because of the technological progresses it has led to. Software radio’s legacy indeed is that it has been and still is a catalyst for the wireless innovation. We conclude by showing that software radio will be used to its full potential when it will be the support technology for other and more complex fields such as cognitive radio.