The present study aims to conduct a comprehensive investigation of flashcard software for learning vocabulary in a second language. Nine flashcard programs were analysed using 17 criteria derived from previous studies on flashcard learning as well as paired-associate learning. Results suggest that in general, most programs have been developed in a way that maximises vocabulary learning. For instance, seven of the nine programs allow flashcard creation, offer multilingual support and allow learners to add contexts, audios or images to flashcards. Furthermore, eight programs provide various types of exercises, and nine programs support scheduling. At the same time, the present study has also shown that existing flashcard programs have some room for improvement. More specifically, most programs are limited in their ability to support data entry, increase retrieval effort and promote generative use of target words. When individual programs are compared, "iKnow!" seems to be the best program among those investigated. It offers the most comprehensive support for data entry, automatically generates distractors for multiple-choice exercises and increases retrieval effort by systematically introducing various types of exercises. The variations among the programs in their design suggest that there do not exist commonly accepted guidelines for how flashcard software should be designed. (Contains 1 note and 2 tables.)