Given the velocity of change in computing and its cultural emphasis on immediacy, preserving hardware and software for future users is a daunting task. As the authors note, the preservation of hardware receives more attention than that of software, but the authors propose a method of enabling software to be used by future researchers. The authors assume that a long-lasting (2,000 to 10,000 years) metallic medium can be devised, and so they concentrate on the software that would be etched on this medium and that would enable scientists in the future to decode it. One side of the disk would contain the target program, and the other side (the key to deciphering the software) would contain a description of a virtual machine that would run the software. The authors present the two elements of the key side of the disk: the label, which explains how to interpret the header, and the header, which contains instructions on how to write an emulator to execute the program. If a researcher from the future can interpret the label, there is then a pathway to reproduce the target program.

The authors present a plausible protocol for making software accessible to future scientists, but it rests on the assumption that future researchers will be able to understand the keys and act on them, and that they will be able to understand what programming languages and software are. The authors should consider using more graphical as opposed to textual descriptions in future work.