Library of Congress researcher David Gibson has discovered the source code for the unreleased PlayStation Portable version of Apogee Software’s Duke Nukem: Critical Mass while cataloging video game materials for the library’s Moving Image section. Gibson explained his discovery and his subsequent efforts to examine the game’s assets in an article published today on the Library’s digital preservation blog, which was subsequently highlighted by Other Ocean developer and video game archivist (and former Gamasutra editor) Frank Cifaldi on Twitter. Gibson’s account is fascinating, and worth reading in full for any developers interested in what this unreleased version of this Duke Nukem game looked like or the challenges contemporary video game archivists face. According to Gibson, the Library of Congress receives hundreds of video games every year as part of the copyright registration process, and many of those games come with extra discs holding supplementary material like documentation, gameplay footage — or source code. When contacted by Gamasutra via email, Gibson stated that he does not believe the Library currently holds source code for any other unreleased games. However, he says “there is still a chance that a DVD-R which we believed contains video of game play could contain the code and assets for a game,” and he plans to “undertake a project to inventory those discs to find out if we do in fact have other such examples in the collection.” Gibson is asking developers to submit source code of their own games to the Library of Congress for archival purposes, and he says that a physical code submission — via a DVD-R or hard drive, for example — is ideal at this point. Going forward, the Library of Congress is hoping to make it possible for developers to submit their code digitally via their BagIt utility, one of the Library’s data archiving tools that was developed in partnership with the National Digital Information Infrastructure and Preservation Program.