The majority of the world is multilingual, but inequitably multilingual, and much of the world is also technologized, but inequitably so. Thus, researchers in the fields of computer-assisted language learning (CALL) and second language acquisition (SLA) would profit from considering multilingualism and social justice when envisioning new CALL-SLA interfaces for the future. I first explain the connection I see among multilingualism, digital literacy, and social justice, and I characterize contemporary SLA as transformed by a social turn that is now complete, a bilingual turn slowly underway, and a social justice turn emerging on the horizon. I then review empirical evidence that suggests digital communication encourages multilingual practices, helps users appreciate the open nature of language resources, and perhaps even supports positive multilingual ideologies. Next I offer some illustrations of possible new research questions and CALL-SLA studies that would focus on embracing and exploiting the openness of language resources in language learning, and on doing multilingual learning. Finally, I examine what we know about the digital divide that is relevant to CALL-SLA researchers. I close with a checklist for researchers interested in contributing to these new research interfaces in support of equitable multilingualism in online and offline language learning and teaching.