The Portal to Texas History is a gateway to cultural heritage collections from Texas libraries, museums, archives, historical societies, and private collections. From its initial release in 2004, the Portal's unique visitors had grown from 1,000 per month to over 20,000 per month. The user interface had become dated and the underlying digital asset management system (DAMS) did not readily support implementation of new functionality. The IOGENE project at the University of North Texas Libraries involved family history researchers, a major user group of archives, in a user-centered application development project to redesign the Portal's interface. At the outset of the project, an application development model was created to guide three teams: system development, interface design, and user studies. The legacy DAMS was replaced with an infrastructure and framework of open source components. Specifications and standard practices in critical areas were established. The Portal's newly minted interface and infrastructure debuted in two public releases in 2009. Subsequent to each release, usability tests were conducted and at the conclusion of the project, experiences and accomplishments were reviewed by the project teams. This review informed a revised application development model that may be of value and interest to the both user support staffs and technical organizations at other archives.