Please note:

• Deadline Saturday 12.11. at 18:00. Return by email to pervila at [the department's mail system].
• Groupwork of up to three persons in each group is allowed.

Task description

Read the article The Many Faces of Publish/Subcribe by Eugster et al. The publish/subscribe architecture it describes is at least partially implemented by many social network services today. No doubt, Facebook's (FB's) engineers have also had somebody to read the paper for them.

In each of the following tasks, compare FB with previous paradigms/services: IRC, e-mail, newsgroups, and blogs. You may swap a service for one
of your own if you wish.

1. Does Facebook implement stronger variants of the three decouplings than earlier services?  Give examples of each of the three, if any exist. You can use either the standard features implemented by FB or applications implemented by third parties.
2. Does FB implement all three subscription schemes? How? Do any of the earlier services have equivalent schemes?
3. In terms of functionality, what new properties has FB added, when compared with each of the earlier services? Could the properties have been implemented using combinations of the services?

In grading this exercise, points are based on the detail and wit of the analysis, not the amount of text produced. A well-written answer should show that the author(s) have understood the concepts in the original article, and how they are reflected in real-world examples.