- Diigo allows users to bookmark websites and organize them with tags. Bookmarked pages can be highlighted and personal notes can be added. Users can follow other users and build collaborative groups. - The community feature shows popular links and tags. There is an educator option for classroom use. Tutorials describe using Diigo for literature classes by having students highlight texts and add notes. - Diigo could be modified for language learning by having students highlight grammar points or translate vocabulary in bookmarked texts. However, it may not be suitable for lower levels where handwriting is important. It could work better for higher levels or online classes.