Despite the fact that the first transgenic plants were generated less than 15 years ago, many transgenic crops are now beginning to be widely grown, and the products of these plants are available in the marketplace.  Among these first generation crops are plants that are tolerant of herbicides, plants resistant to viruses and insects, and plants that are being used as 'bioreactors' to produce pharmaceuticals and food additives.  In addition, some recombinant crops have altered nutritional or storage qualities, or are being used to produce industrially important materials, such as specialty oils and plastics.  The rapid advances necessary to generate these crops have come from three areas: basic research in plant molecular biology and physiology; the development of transformation technologies; and improvements in plant tissue culture to regenerate transformed plant cells or tissues.  Although breakthroughs in each of these areas were essential, I shall limit this review to recent advances in transformation and related technologies.  In addition, I shall discuss recent research to understand how transgene integration patterns may affect transgene expression.