The flashcards are saved as PowerPoint presentation files and may include text, images, sounds and LaTeX equations.

Internally, OpenCards relies on Apache POI to render slides from ppt-files.

The SM2 algorithm had been created for SuperMemo in the late 1980s, but still forms the basis of many spaced repetition software applications.

OpenCards started as flashcard learning extension for OpenOffice Impress in spring 2008, from which it inherited the first part of its name.

OpenCards implements no synchronization mechanism, but flashcard sets including their learning states can be synced using services like DropBox.