Only 80 years ago, chasing after a particular Drosophila mutant probably involved no more than a phone call to Thomas H. Morgan. A few years later you could consult Bridges' and Demerec's compendium of mutant stocks. However, the legacy of many years of industrious research on Drosophila is an extraordinarily large selection of modified fly lines, as well as dozens of online research databases and access to the many molecular materials that are required to manipulate the fly genome. The challenge to present workers in the field — one that concerns both the novice and the experienced researcher — is to know which resources are available and where to obtain them.

Kathy Matthews and colleagues have complied a comprehensive survey (page 179) of the most important resources of primary information, materials and services for fly research. Whether you would like information on fly anatomy, a particular P-element insertion line or an embryo injection centre, this article should guide you to the answer. The online databases described in this review are hyperlinked to the relevant site (in the web version of the article), so you can move straight from reading about a resource to tapping into what it can offer.

Of course, it is possible that a mutation, for example, in a genomic location you are interested in is simply not represented on any of the available web sites. The only option then will be to create your own. In their Review on page 167 Koen Venken and Hugo Bellen, survey the most recent and, in their view, most promising advances in fly genetic technology — which go from generating designed mutations to new transgenic methods.

But not all has changed since the 1920s: most fly resources are available at little or no cost, in the generous spirit in which the early drosophilists exchanged their materials and expertise.