This book examines communicative practices in a circuit-board manufacturing plant in California's Silicon Valley, where the employees come from diverse ethnolinguistic backgrounds, their activities involve the use of high-tech equipment and their practices are shaped by, and sometimes contest, local and global forces. Analyses of the data show that learning occurs optimally when workers make strategic use of both their home languages and English within an ecology of semiotic systems. The book demonstrates the importance of accounting for multilingual practices in studies of multimodality. Through detailed ethnography it brings the reader to a better understanding of learning-in-practice in work environments, where the complexities and accelerated growth of new technologies along with a globalized world produce new forms of multilingual and multimodal communication.