Since VirtualBox is designed to provide a generic virtualization environment for x86 systems, it may run operating systems of any kind, even those that are not officially supported by Sun Microsystems. However, our focus is to optimize the product's performance for a select list of guest systems:
All versions/editions and service packs are fully supported; however, there are some issues with older service packs. We recommend to install service pack 6a. Guest Additions are available with a limited feature set.
All versions/editions and service packs are fully supported (Vista as 32 bits and 64 bits, under the preconditions listed above). Guest Additions are available.
Limited testing has been performed. Use beyond legacy installation mechanisms not recommended. No Guest Additions available.
Limited support.
All versions/editions are fully supported (32 bits and 64 bits). We strongly recommend using version 2.6.13 or higher for better performance. However, version 2.6.18 (and some 2.6.17 versions) introduced a race condition that can cause boot crashes in VirtualBox; if you must use a kernel >= 2.6.17, we advise to use 2.6.19 or later. Guest Additions are available.
Fully supported (32 bits and 64 bits). Guest Additions are available with a limited feature set.[5]
Limited support. Guest Additions are not available yet.
Versions 3.7 and 3.8 are supported. Guest Additions are not available yet.
Requires hardware virtualization to be enabled. We officially support MCP2 only; other OS/2 versions may or may not work. Guest Additions are available with a limited feature set.[6]