VMware (VMW) still may be a dominant force, but open source virtualization continues to evolve. That was clear last week in the latest release of QEMU, the emulator that provides the basis for many open source virtualization solutions across desktops, servers and the cloud.

Just before Thanksgiving, the QEMU team released QEMU 1.7.0. The update introduces a sizable list of new features, with highlights that include:

  • Several enhancements to audio support within guest virtual machines.
  • Performance improvements for USB 3.0, an important feature on many different hardware profiles.
  • Better access for guest machines to the ACPI firmware of the host's underlying hardware, which "will in the future enable new features without modifications of all firmware components (SeaBIOS, OVMF, CoreBoot)."
  • Various improvements to the tools and interfaces for handling virtual disk images, including not only the open source qcow format but also VMware's VMDX files (which are now an open source format, but were not originally) and VHDX images from Microsoft's Hyper-V hypervisor.

For the most part, the features updates in QEMU 1.7.0 are of the type that only geeks will fully appreciate—let alone understand. But QEMU, unlike the virtualization product from Microsoft (MSFT) and VMware, has never touted itself as a user-friendly platform.

Coupled with friendlier tools and interfaces, however, QEMU has provided the basis for a variety of open source virtualization solutions from channel partners and ISVs. It remains a potent counterbalance to proprietary virtualization technologies.

And many of the feature updates in QEMU 1.7.0 also affect KVM, a closely related open source virtualization solution. The main differences between QEMU and KVM are that the latter uses CPU virtualization extensions instead of emulation, and runs only on Linux hosts (although it can power a variety of guest operating systems, including most versions of Windows). But both platforms share code and, together, constitute the open source ecosystem's main contender within the virtualization market, where competition will only grow as the cloud continues to evolve.