Parallel DNA assembly methods allow multiple fragments of DNA to be compiled in a desired order in a single reaction. Several methods enable the efficient one-step assembly of multiple DNA parts into a suitable plasmid acceptor at high efficiency. Type IIS-mediated assembly offers the specific advantage of a one-step reaction that does not require proprietary reagents or the amplification and purification of linear DNA fragments. Instead, multiple plasmids housing standardized DNA parts of interest are combined in an enzyme cocktail. To make these standard parts, DNA sequences with defined functions are assigned specific sequence features. This allows parts to be interoperable and reusable. The availability of collections of DNA parts and molecular toolkits that allow the facile assembly of multigene binary constructs and the establishment of standards for the creation of new parts means Type IIS-mediated assembly has become a powerful technology for modern plant molecular biologists.