1. A computer-implemented method comprising: identifying, by a computer, a visual object displayed within a digital video; providing to a user a first web-based user interface portion for annotating the digital video, the first web-based user interface portion comprising visual representations of a plurality of different annotation types; receiving a selection from the user of one of the annotation types; providing to the user a second web-based user interface portion comprising at least one input area for specifying a link for a new annotation for the visual object; receiving a request from the user to add an annotation of the selected annotation type to the visual object, the request comprising a designation of the link for the annotation; determining, by the computer, a plurality of spatial and temporal positions of the visual object across a corresponding plurality of frames of the digital video; adding the annotation to an annotation database in association with the digital video such that the annotation is displayed during playback of the digital video and moves along with the determined plurality of spatial and temporal positions of the visual object, and such that selection of the annotation redirects to a target of the link; and responsive to receiving a request for the digital video from a client device: detecting that the client device is in a locale with a language different from a language of text of the annotation; and responsive to the detecting, altering the annotation to be displayed, wherein altering the annotation comprises translating the text of the annotation according to the language of the locale.
2. The computer-implemented method of claim 1 , further comprising determining, by the computer, whether the user is authorized to annotate the digital video.