Progress in software defined radio has been rapid, since the term was first coined in the mid 1990s. In this brief overview we summarise some of the recent advances in software defined radio from a range of technology perspectives — radio frequency design, baseband reconfigurability, reconfigurable applications and protocols and regulatory (and related network) aspects. Our frame of reference for this article is commercial mobile telecommunications, although many of the technology advances are of relevance and application in other arenas, such as defence, satellite communications and broadcasting. Software defined radio has come a long way very quickly, but in reality is still in its infancy — the next decade will see substantially further advances. This paper draws heavily upon two books on this subject recently edited by the author — the contributors to those books are listed at the end of this article and the work of these pioneers of software radio is fully and most gratefully acknowledged. Additional detail on issues covered in this article may be found in specific chapters of these books, referenced as [Name] within the text.