A flexible Java library for HTML5-based annotation of 50+ types of documents and images. Supported file formats include: PDF and Microsoft Word documents, Excel spreadsheets, PowerPoint slides, Visio, CAD, raster images and other common document types.

Key features include:

1. Platform independent. GroupDocs.Annotation for Java works across all popular platforms, including iPad, iPhone, Android, Mac and PC. All a user needs to annotate a document is an HTML5-compliant browser.

2. High fidelity true-text rendering. The library renders documents as text files, so that users can search for, select and copy text right from documents displayed within your app or website.

3. A wide set of annotation tools:
- Sticky notes with rich text
- Point annotations (allows adding notes to any point in the document)
- Area annotations (allows commenting on an area marked up with a rectangle)
- Text annotations (allows striking through/underlining and commenting on text)
- Text replacement (allows editing text)
- Text/area redaction (allows blacking out text/area)
- Polyline (allows drawing freehand lines)
- Arrows
- Watermarks
- Undo/redo

4. A customizable UI. GroupDocs.Annotation for Java has a convenient web UI, designed to make it easy to annotate large documents in a browser. It allows end users to:
- Turn document pages with the click of a button
- Jump straight to a selected page
- Preview pages with thumbnails
- Quickly navigate between annotations
- Print and export annotated documents to PDF
- Collaborate on documents in real time.

5. Support for native PDF annotations. Annotations made in GroupDocs can be converted to/from native PDF annotations for further editing.

Finally, GroupDocs.Annotation for Java can be easily integrated into any project, as it doesn't require any client-side installation at all. To test the library without any restrictions, please feel free to contact GroupDocs sales for a 30-day fully-functional trial.