No specific info about version 5.1. Please visit the main page of PDF Converter on Mac Informer.
iStonsoft ePub Converter for Mac lets you create ePub files.
Application that helps you to convert any Adobe PDF document into SWF files.
iOrgsoft PDF to Epub Converter for Mac allows you to convert PDF to ePub format.
Application to convert any PDF documents to images files.
It helps you convert PDF files to HTML web page for mac without Adobe Acrobat.