Adobe Acrobat Reader, Adobe Acrobat DC, SumatraPDF, PDF-XChange Viewer, Okular, Foxit Reader, Xodo, Xournal++, Evince, Kami, Chrome PDF Viewer Plug-in, Skim, EBookDroid, zathura, Document Viewer, Firefox PDF Viewer (PDF.js), Butterfly, NightPDF, Kavita, Google Docs Viewer, Nuance PDF Reader, Nitro PDF Reader, STDU Viewer, RepliGo Reader, Google PDF Viewer, iTop PDF, Librera Reader, PSPDFKit, Qoppa PDF Studio, MJ PDF Reader, Xpdf, Atril, Icecream PDF Editor, WinDjView, Lumin PDF, Librum, Shelf (Maui Applications), Ashampoo PDF Free, Pdf Viewer Plus, Hyphen, qpdfview, SlimPDF Reader, Paperboy, pdf.io, CovePDF, Secure PDF Viewer, Gaaiho PDF Reader, Openlib, PDFlite, PDF Previewer for Windows 8, Haihaisoft PDF Reader, SourcePDF, modern computer flatboat, APV, PDF Viewer Pro by PSPDFKit, PDF Reader Air, Orion Viewer, BePDF, VuDroid, Read Right, PDF Reader Online, Sioyek, Comix, Kdan PDF SDK, Altarsoft PDF Reader, Hamana are some alternatives to MuPDF.