The point of departure for this article is the contrast between the theoretical landscape within view of language teaching professionals in 1991 and that of today. I argue that the pragmatic goal of computer-assisted language learning (CALL) developers and researchers to create and evaluate learning opportunities pushes them to consider a variety of theoretical approaches to second language acquisition (SLA), which have developed, in part, in response to the need to theorize the role of instruction in SLA. To illustrate connections between SLA and CALL, I touch on multiple theoretical perspectives grouped into four general approaches: cognitive linguistic (Universal Grammar, autonomous induction theory, and the concept-oriented approach); psycholinguistic (processibility theory, input processing theory, interactionist theory); human learning (associative-cognitive CREED, skill acquisition theory); and language in social context (sociocultural, language socialization, conversation analysis, systemic-functional, complexity theory). I suggest that such theoretical approaches can be useful in the development and evaluation of CALL materials and tasks. Finally, I propose that the expanding use of technology changes the nature of communicative competence theory, challenges SLA theory, and increases the number of consumers for SLA research.