Lots of changes: all line stroking is now done with a queue, which means if a line’s thread gets cancelled pre-draw, it will get picked up by the next thread and so on. This results in much smoother drawing and less ‘stepping’ on round edges. Also, tools may now provide controls in the ‘tool palette’ window, and the first one to do so is the new paintbucket tool which supports a threshold amount as well as an opacity setting. There is also now a Brightness/Contrast operation and the preview/options dialog was migrated from the filters system.