Deletes a single file, a specified directory and all its files and subdirectories, or a set of files specified by one or more FileSets. When specifying a set of files, empty directories are not removed by default. To remove empty directories, use the includeEmptyDirs attribute.
If you use this task to delete temporary files created by editors and it doesn't seem to work, read up on the default exclusion set in Directory-based Tasks, and see the defaultexcludes attribute below.