How's this for creativity? Take Escherichia coli bacteria. Transform them into light-sensitive organisms by fusing a photoreceptor from the cyanobacterium Synechocystis to a protein in the E. coli membrane. Make a film (in both senses) of such bacteria and use them to record an image with a resolution of 100 megapixels per square inch. For the result, see page 441. For other bio-widgets, see page 417.

This technology allows biological components, circuits and potentially replicating organisms to be developed from scratch.

Achieving this neat trick required researchers to engineer component parts of gene circuitry. This bottom-up engineering is often referred to as synthetic biology. It is indeed a type of biology: developing circuits that achieve what nature has evolved over eons is one way of gaining insight into what makes life tick. But it is also engineering, of a type quite different to the simple manipulation of bits of DNA to incorporate or knock out existing genes. This technology allows biological components, circuits and potentially replicating organisms to be developed from scratch, possibly based on different genetic codes from those found in the wild.

In this special issue on synthetic biology, some of the field's founding figures describe the technical challenges of such engineering (see page 443), review the scope and foundational principles of the discipline (page 449), and explore ways in which socially responsible synthetic biologists can gain public trust by focusing on safety (page 423).

Last year we expressed the hope that synthetic biologists would act to engage with stakeholders (Nature 431, 613; 200410.1038/431613b). Nature is pleased to highlight community thinking on such issues, and welcomes, and will participate in, stakeholder discussions at the second international meeting on synthetic biology at Berkeley next May. And finally, knowing that a graphic can help get the message across to a wider audience, we are delighted to publish a cartoon introduction to the field.