-Diigo allows users to bookmark websites with tags such as; education, fun, etc… that allow other users to search through useful websites that others have found.

-These bookmarked pages can be selectively highlighted in several colors for easy reference. (though I haven’t seen this done in any of the listings I’ve investigated.)

-Personal notes can also be added for reference by users when they mouse over a section of the website. (again, I haven’t seen this, people just seem to suggest websites and write comments in a discussion board attached to every site.)

-You can opt to follow the submissions of users whose submissions you enjoy.

-Users can build groups for collaborative research or just to selectively pool what they find. Diigo groups are just another way to helpfully limit your search results.

-The community tab shows the most popular links and recommended tags to search through to get you started with Diigo.

-There is an Educator option for teachers to use Diigo in the classroom.

-Many of the tutorials that I was able to find for using Diigo in the classroom were for a text-based L1 literature class. These often involved having students highlight text in different colors to show reading comprehension and adding meta-data notes to mark character development and plot progression.-These same elements could be modified for an L2 class; highlight grammatical points for homework, such as highlighting all the use of passive-voice in green, irregular plurals, etc… Or using the meta-data notes to mark and translate all the adjectives and note what noun they are modifying.

Conclusion

-I don't imagine this would be very efficiently useful to a lower level class, as it seems to be purely textual and has very little student interaction possibilities. At best I think low level students could build discussion boards based around audio/video submissions.-Could be more helpful with homework assignments, but I think handwriting is very important at lower levels.

-Could have many possibilities for an EAP class, by requiring that the students comment on certain elements as they read or by highlighting theses or transitions. Anything more focused on accurate reading and writing at higher levels.

-At lower levels I think it could be used to activate student knowledge by work on recognizing new grammar points before they are expected to produce them.

-I see Diigo as primarily an L1 English tool that could more useful in a higher level ESL/EFL class, but still a bit unnecessary unless your Class is online, in which case I’m sure there are bigger issues to resolve.