Over the last decade, the number of one-to-one laptop programs in U.S. schools has steadily increased. Though technology advocates believe that such programs can assist student writing, there has been little systematic evidence for this claim, and even less focused on the benefits of specific technology use by diverse learners. This dissertation investigates the overall effect of a one-to-one laptop program--combined with a curriculum reform focused on authentic writing--on upper elementary students' writing outcomes and processes; and the use of two specific social media tools--microblogging and Google Docs--on students' participation, interaction, and achievement within the one-to-one laptop program. This dissertation finds that at-risk learners used their netbooks in school for writing-related activities more frequently than their counterparts, and Hispanics and students from low-income families also benefited from the laptop program the most, in terms of their standardized writing achievement gains. Further investigation of students' use of microblogging and Google Docs in two specific schools suggests that well-designed technology-facilitated writing activities among diverse upper elementary and middle school students can result in increased participation, interaction, and collaboration, leading to improved students' language and literacy development. This dissertation provides policymakers and educators with evidence of the educational benefits of investing in technology programs in schools to improve students' literacy development. It also provides school administrators and teachers with practical examples of the integration of social media into classroom activities to facilitate students' participation, interaction, and writing development. Finally, this dissertation enriches current literacy research by investigating how to bridge students' out-of-school and in-school literacy activities and, ultimately, how to enhance educational equity by providing diverse learners equal access to digital resources that are indispensible to literacy development. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]