20.PearltreesPearltree can be described as a free curation platform that is used by millions of people.This social bookmarking site can be used easily on any device. With this platform, users get the access to save everything they wish to, including the web pages, files, photos, videos, notes, and others.An amazing feature that Pearltree comes with is a chrome extension that allows users to save anything online.21.DiigoDiigo is an incredible source that you can use to bookmark all the latest blog post links.The platform is quite easy to use and understand, where users are given the access to bookmark any number of pages or links of their site without any problem.Besides that, you can use Diigo to store any information or highlight any part of the website page and also attach sticky notes to get easy access in the future.22.Facebook groupFacebook is the world’s largest social network where more than 1.5 billion groups have been created.These FB groups have topics belonging to diverse categories including parenting, pet care, art, religion, and more.The platform is completely free to use but to get access to the Facebook group, one needs to create a Facebook account first using their Gmail or phone number. Once an account has been created, you can search for the groups and join them that serve your interest.23.BibsonomyA perfect combination of social bookmarking sites and publication sharing systems is Bibsonomy.This platform not only allows you to create bookmarks but also add links. Besides that, users are also given the access to create and join groups of their choice.Furthermore, one can also collaborate with their colleagues and get their hands on unique articles and links for daily work purposes.