AHTL has participated in several cooperative projects to digitize its materials. Examples include:
- Contagion: Historical Views of Diseases and Epidemics
- Harvard-Google Project
- Holocaust Rescue and Relief: Digitized Records of the Unitarian Universalist Service Committee
- Immigration to the United States, 1789-1930
- New Testament and Archaeological Slides
- Postcards of Unitarian and Universalist Church Buildings
- Religious Aspects of the American Civil War
- Thanksgiving Day Sermons
- Unitarian Universalist Congregations
- Colonial North America
The library also maintains a growing body of Featured Images and has created the following online exhibits: