Few funded research projects in computer science go on for decades. It’s even questionable whether any project should be sustained that long. Nevertheless, the Protégé project at Stanford University began in the 1980s and is still going strong, helping developers to construct reusable ontologies and to build knowledge-based systems. The recognition of our work at the International Semantic Web Conference in October 2014 with the “Ten Years” Award was a great honor. The award has provided an opportunity for reflection—both on the Protégé project itself and on the need for computational infrastructure in the AI community.

Protégé has become the most widely used software for building and maintaining ontologies. It is by no means the only solution, and there are known problems with Protégé, but we appreciate that the system is extremely popular. Although his study is now a bit dated, Cardoso (2007) surveyed the Semantic Web community and found that two-thirds of his respondents used Protégé. To date, more than 250,000 people have registered to use the software. Many Fortune 500 companies use Protégé to build their ontologies. Important government projects, such as the development of the National Cancer Institute Thesaurus (Noy et al., 2008; Figure 1) and the World Health Organization’s International Classification of Diseases (ICD-11; Tudorache et al., 2010) depend on the software.