When comparing Proxmox vs Oracle VirtualBox, the Slant community recommends Oracle VirtualBox for most people. In the question“What is the best Virtual Machine (VM) for developers?” Oracle VirtualBox is ranked 1st while Proxmox is ranked 6th. The most important reason people chose Oracle VirtualBox is:
Works with [Vagrant](http://www.vagrantup.com/), an awesome tool for managing and deploying virtual machine images.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Free
Free with no restrictions like missing backup facilities.
Pro Works with Vagrant
Works with Vagrant, an awesome tool for managing and deploying virtual machine images.
Pro Free, mostly open source and cross-platform
VirtualBox is available for free with source code available here. A "VirtualBox Extension Pack" that includes virtual USB 2.0, VirtualBox RDP & PXE boot support is available only under a commercial license. VirtualBox is available on Windows, Linux, OSX and Solaris.
Pro Can do snapshots
VirtualBox is capable of taking whole-system snapshots and writing them to a backing file.
Cons
Con No Windows installer
Proxmox is Debian based, and although it can be installed in an existing Debian system it is easier to install from the .iso image.
Con Inferior performance
Apart from second-class performance in virtualization, there are some visual glitches with Windows 8.1 on Mavericks.
Con Confusing interface and lacking usability features
VirtualBox might be a bit confusing for beginners - it requires an understanding of a lot more technical details than other VMs.