Manage interactive and explanatory annotations to specific words, phrases and regions of the documents content in any cross platform application. GroupDocs.Annotation for .NET API allows developers to seamlessly enhance their applications with the capability to annotate text or images in a document. Annotation can be applied in form of comments, explanations with highlighted notes, watermark, polyline and much more. Annotator API supports PDF, Microsoft Word DOCX, Excel XLSX and PowerPoint PPTX documents.