In the interest of the maize research community, the Iowa State Transformation Facility and Lawrence-Dill Plant Informatics and Computation Lab in collaboration with MaizeGDB has released a beta-version of the B104 maize genome and structural annotations prior to scientific publication in accordance with guidelines set forth by the Toronto agreement for prepublication data sharing (Nature. 2009 461:168). The above groups reserve the first right to publish on the available B104 data including but not limited to whole-genome comparisons, genes, structural annotations, functional annotations, and genome-wide association studies. The group also requests the first opportunity to improve the sequence and annotations for a full official genome release. Under the Toronto agreement, users can use the B104 sequence and annotation to study the individual or small sets of genes and localized regions of the genome. Any redistribution of these data should include the full text of the data use policy.