libguestfs is a set of tools for accessing and modifying virtual machine (VM) disk images. You can use this for viewing and editing files inside guests, scripting changes to VMs, monitoring disk used/free statistics, P2V, V2V, performing partial backups, cloning VMs, and much more. libguestfs can access nearly any type of filesystem including: all known types of Linux filesystem (ext2/3/4, XFS, btrfs, etc.), any Windows filesystem (VFAT and NTFS), any Mac OS X and BSD filesystems, LVM2 volumes, MBR and GPT disk partitions, raw disks, qcow2, CD and DVD ISO images, SD cards, and dozens more. libguestfs doesn't need root permissions.
RemoteBox is a graphical tool which lets you administer guests or virtual machines running under VirtualBox on a remote server or even your local machine if desired. You may, for example, have a root server on the Internet, a server at home, or a server at work running VirtualBox but want to have the convenience of managing the guests easily from your local machine. The virtual machines run in headless mode, which means you don't need an active graphical display on the server but you can still connect and view the displays of the guests. The goal of RemoteBox is to provide a GUI that should be familiar to VirtualBox users while allowing them to administer a remote installation of VirtualBox. It does this via the VirtualBox API and SOAP interface, which are exposed when running the VirtualBox Web service. You can also use RemoteBox simply as an alternative interface for managing VirtualBox on your local machine.
Proxmox is a Debian-based bundle of OpenVZ, KVM, and a Web based management GUI. It supports high-performance container-based virtualization of Linux workloads, as well as lower performance KVM hardware assisted virtualization. It supports any hardware that the Linux kernel supports, and will permit live migration of running OSIs with shared storage configurations (DRBD, CIFS, NFS, etc.). It comes bundled with many virtual appliance templates (Drupla, Moodle, FreePBX, etc.) and generic OSI appliances (Fedora, Debian, Ubuntu), as well as a faculty for building arbitrary Linux based appliances. It can be used for virtual desktop infrastructure (VDI) and virtual server infrastructure (VSI). It supports almost any x86/x64 OS in a KVM container and any Linux-based OS in OpenVZ.
imvirt is a Perl script that tries to detect if it is called from within a virtualization container. This is detected by looking for well-known boot messages, directories, and reading DMI (Desktop Management Interface) data. The following containers are detected: Virtual PC/Virtual Server, VirtualBox, VMware, QEMU/KVM, Xen (para and non-para virtualized), OpenVZ/Virtuozzo, UML, and any HVM providing CPUID 0x40000000 detection.
Nuxis is an integrated solution for virtualization management. Some of its features are centralized management of nodes/physical machines and virtual machines, management of virtual networks, storage management, ISO management, monitoring and statistics charts, backup/restore of appliance configurations, import from and export to other virtualization systems using the OVF format, access control, support for multiple operating systems on 32-bit and 64-bit architectures, including Linux and Windows, paravirtualized hardware acceleration drivers, live migrate, PXE boot, Web management, storage management with LVM, and more.
Collax V-Cube+ is a HA cluster management suite based on a 64bit Linux system and KVM to provide server virtualization. It offers solutions for single virtualization hosts, as well as high availability management on two or more nodes, allowing embedded HA storage using DRBD and iSCSI. By using live snapshots, automatic live migration, and incremental backups, the availability of virtual machines is increased tremendously in case of hardware and software maintenance or even hardware failures. Virtual network switches and the protocols GVRP, LLDP, and RSTP help to set up a virtual DMZ.