Hirokazu Kato, a professor at the Nara Institute of Science and Technology (NAIST) in Japan, embarked on his journey in augmented reality by developing ARToolKit in 1999, which incorporated as ARtoolworks in 2001. This groundbreaking open-source computer tracking library, pivotal for overlaying virtual imagery onto the real world, significantly influenced AR application development globally by making it accessible to thousands of developers, leading to a mass market adoption of AR experiences on PC webcams.

Through ARToolKit, Kato addressed critical challenges in AR, such as viewpoint tracking and virtual object interaction, by enabling real-time calculation of camera positions relative to markers. This innovation laid the foundation for mobile AR, with ARToolKit's evolution facilitating its application on platforms like Symbian, iOS, and Android.