It is impossible for a single individual to fully curate a genome with precise biological fidelity. Beyond the problem of scale, curators need second opinions and insights from colleagues with domain and gene family expertise, but the communications constraints imposed in earlier applications made this inherently collaborative task difficult. Apollo, a client-side, JavaScript application allowing extensive changes to be rapidly made without server round-trips, placed us in a position to assess the difference this real-time interactivity would make to researchers’ productivity and the quality of downstream scientific analysis. To evaluate this, we trained and supported geographically dispersed scientific communities (hundreds of scientists and agreed-upon gatekeepers, in ~100 institutions around the world) to perform biologically supported manual annotations, and monitored their findings. We observed that: 1) Previously disconnected researchers were more productive when obtaining immediate feedback in dialogs with collaborators. 2) Unlike earlier genome projects, which had the advantage of more highly polished genomes, recent projects usually have lower coverage. Therefore curators now face additional work correcting for more frequent assembly errors and annotating genes that are split across multiple contigs. 3) Automated annotations were improved as exemplified by discoveries made based on revised annotations, for example ~2800 manually annotated genes from three species of ants granted further insight into the evolution of sociality in this group, and ~3600 manual annotations contributed to a better understanding of immune function, reproduction, lactation and metabolism in cattle. 4) There is a notable trend shifting from whole-genome annotation to annotation of specific gene families or other gene groups linked by ecological and evolutionary significance. 5) The distributed nature of these efforts still demand strong, goal-oriented (i.e. publication of findings) leadership and coordination, as these are crucial to the success of each project. Here we detail these and other observations on collaborative genome annotation efforts.