GroupDocs.Annotation Cloud is a REST API and universal document annotator that supports almost all common business document and image file formats.
File Format Description Annotate DOC, DOCX Word Document ✔ OTT Open Document Standard Format ✔ ODT Open Document Text File Format ✔ DOCM Microsoft Word Open XML Macro-Enabled Document ✔ DOT Word Document Template File ✔ DOTX Word Open XML Document Template ✔ DOTM Word Open XML Macro-Enabled Template File ✔ RTF Rich Text File Format ✔ TXT Plain Text File Format ✔ PDF Portable Document Format ✔ PPT, PPTX Presentation Document Format ✔ PPSX PowerPoint Open XML Slide Show ✔ ODP OpenDocument Presentation File Format ✔ OTP OpenDocument Presentation Template ✔ XLS, XLSX Cells Document Format ✔ XLSB Microsoft Excel Binary Spreadsheet File ✔ XLSX Microsoft Excel Open XML Spreadsheet ✔ DICOM Digital Imaging and COmmunication in Medicine ✔ OTP OpenDocument Presentation Template ✔ DJVU DjVu Format ✔ EMF/WMF Enhanced MetaFile / Windows MetaFile ✔ CAD Computer-Aided Design ✔ EML/EMLX Email Markup Language ✔ HTML HyperText Markup Language ✔ MHTML MIME HTML File ✔ JPEG Joint Photographic Experts Group ✔ TIFF Tagged Image File Format ✔ BMP Bitmap ✔ GIF (static images without animation) Graphics Interchange Format ✔ VSD Microsoft Visio Drawing ✔ VDX Microsoft Visio XML File Format ✔ VSS Microsoft Visio Stencil File Format ✔ VSDM Microsoft Visio Macro-Enabled Drawing File ✔ MSG Email Message ✔...Standard Format ✔ Open Document Text File Format ✔ Microsoft Word...Template File ✔ Rich Text File Format ✔ Plain Text File Format ✔ Portable...