The Insense VM is a specialised Java virtual machine for running Insense programs on wireless sensor nodes. The VM runs on top of InceOS, a purpose-built operating system. A split VM architecture is used, in which Insense programs are compiled to Java classes, then linked and compacted on a more powerful machine into a form suitable for execution by the VM. Measurements demonstrate that the virtual machine achieves good performance and memory usage for realistic Insense programs.