Let's say you have found some code that you don't understand on line 65 of a file. Who do you ask about it? Well you could start by looking at the resource history for the file, but that won't tell you who changed that particular line. This is why the Annotate command is useful. Sometimes jokingly referred to as the blame, it allows you to pick any ASCII file (see note on binary files) and get a listing of who changed what line.
The Team > Show Annotation action is available from the following places: History View, Repository Explorer, Synchronize View, the Project and Package Explorers, and text editor context menus. The action works in a Quick Diff flavor and offers the following features:
The annotate command will only work with files that are marked as ASCII in the CVS repository. Also, the command will open a text file to show the changes even if the associated editor in the workbench is a non-text editor. For example, if you run annotate on a plugin.xml file a simple text editor will be opened instead of the full PDE editor.