Whyteboard is a painting whiteboard application that runs on Linux and Windows, that allows the annotation of PDF, PostScript documents and various image formats with common drawing tools (pen, rectangles, ellipses, text). A history of your drawing is stored, facilitating the replaying of your drawing.
Whyteboard enables tabbed painting, with multiple sheets that can be drawn upon, with each sheet having its own live-updating thumbnail. This allows the editing of multiple documents or images inside a single instance of Whyteboard. Each sheet has its own undo and redo operations as well as its own history replay list.
1T3XT offers a suite of products that are useful to create and/or manipulate documents, more specifically PDF and RTF documents. There's some support for XML and HTML, but this isn't the core business of iText.