What are the best tools for visually comparing PDFs?

Platforms:Windows, Linux, Mac

Android version:Seven Segment recognitioon

Platforms:Windows; Mac; Android; iOS

Real-time collaboration:No

Exports:.pdf; .ps; .eps; .html; .htm; .jpg; .jpeg; .jpe; .jpf; .jpx; .jp2; .j2k; .j2c; .jpc.png; .pptx; .rtf; .txt; .tif; .tiff; .xlsx; .doc; .docx; .xml; .csv

Imports:.doc; .docx; .xls; .xlsx; .ppt; .pptx; .txt; .rtf; .ps; .eps; .prn; .bmp; .jpeg; .gif; .tiff; .png; .pcx; .emf; .rle; .dib; .wpd; .odt; .odp; .ods; .odg; .odf; .sxw; .sxi; .sxc; .sxd; .stw; .psd; .ai; .u3d; .prc; .dwg; .dwt; .dxf; .dwf; .dst; .xps