Apeirogon
Apeirohedron
Apel (emacs)
A People's History of the United States
A Perfect Circle
A Perfect Day for Love Letters
A Perfect Stranger
A Perfect Vacuum
A Perfect World
Apertium
Apert syndrome
Aperture (software)
A Pest in the House
Apethorpe
APEXC
Apex Hides the Hurt
Apex Records (Canada)
APEX (video game)