Seven is a rich-text editor that uses RTF and RTFD as native formats and can read and write Word 97/2003/2007, OpenDocument, and HTML formats. Along with standard editing features, it offers extras for technical writing, including support for embedding multiple-resolution images in RTFD (for standard and Retina displays), correct handling of RTFD documents under Subversion control, and a highlighter that supports highlighting in overlapping colors and highlighting multiple times to darken colors.