Portable-VirtualBox is a free and open source software tool that lets you run any operating system from a usb stick without separate installation. Developed by Runar Buvik
License: Open Source
VMware Fusion is a software hypervisor developed by VMware for Macintosh computers. VMware Fusion allows Intel-based Macs to run operating systems such as Microsoft Windows, Linux, NetWare, or Solaris on virtual machines, along with their Mac OS X operating system using a combination of paravirtualization, hardware virtualization and dynamic recompilation. Developed by VMware
License: Commercial
VMware Fusion is a robust virtualization tool designed for macOS users, offering advanced features and better integration, but at a cost. Portable Virtualbox, on the other hand, is a free, lightweight option that is more flexible in terms of portability but lacks some advanced capabilities.