Abstract: Systems, methods, and non-transitory computer-readable media can acquire content items in a content sharing system from a time a user last accessed the content sharing system. The content items can be ranked based on relevance of the content items. An update including at least one content item selected from the content items for access by the user can be generated.

Abstract: Uses of an online system include a target user and other users that are connected to the target users. The online system presents a content item received from a target user to the other users. The online system receives comments on the content item from the users and a selection of one of the comments from a user. The online system provides one or more types of actions (e.g., adding the comment to the content item or highlighting the comment) on the comment that the user can take. Upon receiving a selection of adding the comment, the online system modifies the content item to include the comment. Upon receiving a selecting of highlighting the comment, the online system associates a highlighting feature to the comment. The online system provides the modified content item or highlighted comment for display to the plurality of users.

Abstract: Systems, methods, and non-transitory computer-readable media can provide a scalable composer interface for creating and sharing content through a social networking system. A content item being accessed can be determined. At least one option for interacting with the content item can be predicted based at least in part on the content item being accessed. The at least one predicted option can be provided in the scalable composer interface, wherein the at least one predicted option is able to be selected to interact with the content item being accessed.

Abstract: Systems, methods, and non-transitory computer-readable media can determine user activity of users of a content sharing system. Whether the user activity of the users satisfies one or more criteria can be determined. A space within which the users can exchange content items can be generated based on satisfaction of the one or more criteria.

Abstract: Systems, methods, and non-transitory computer-readable media can be configured to present a comment thread including at least one comment. A selection of the at least one comment presented in the comment thread can be determined. A reply thread based at least in part on the at least one comment can be presented.

Abstract: Systems, methods, and non-transitory computer-readable media can acquire content items in a content sharing system from a time a user last accessed the content sharing system. The content items can be ranked based on relevance of the content items. An update including at least one content item selected from the content items for access by the user can be generated.

Abstract: For a user in a social networking system, the social networking system provides photo spaces to facilitate communication between users. Icons represent other users, and the user interacts with an icon to view photos or other media items with which both the user and another user are associated (e.g., in which both users are visually present). When a user interacts with a photo or other media item, the social networking system generates a chat user interface for the user to have a private conversation with the second user with reference to the photo.

Abstract: A social application provides a user interface that allows private or non-public interactions by users in a relationship (e.g., a dating or family relationship), which acts as a “private space” for those users. The private space can be created behind a main interface of a social application so that it is easily accessible by swiping away or otherwise revealing the private interface. Users can easily return to the main interface, such that a user can flip back and forth between private and more public environments. The private space can include user interfaces accessible via tabs or links, such as a homepage interface, a chat interface, a photos interface, and a dates interface that together allow users to communicate privately, share photos and important dates. One user can also receive notifications in either the main or private interfaces that notify the user of the other user's actions in either interface.

Abstract: A social networking system enables users to interact through a content item in real time by presenting an interaction bar to a user viewing a content item page associated with the content item. The social networking system presents the content item pages for content items along with a content item header. The content item header remains at a fixed position on the display of a viewing user's client device at the top of the display. If the social networking system receives an interaction with a content item, the social networking system can identify users who are viewing the content item page associated with the content item and present an interaction bar that describes the interaction in the content item header. To determine whether to present an interaction bar to a viewing user, the social networking system can calculate an affinity score of a viewing user for the interaction.