VirtualBox 5.1 promises to be a major release that will introduce a significant number of new features and improvements, among which we can mention a revamped installer based on the latest Qt5 technologies, and the ability to rebuild kernel modules without the Dynamic Kernel Module Support (DKMS) framework. A great number of performance improvements are also coming to VirtualBox 5.1 thanks to the implementation of new APIC (Advanced Programmable Interrupt Controller) and I/O APIC technologies. And it also looks like the upcoming release sports multiple enhancements to Solaris operating systems.