1. A method of constructing a secure and flexible operating system, the method comprising: installing a microkernel on a computing device; executing a first user application in a first operating system of a first virtual machine on the microkernel; executing a second different user application in a second different operating system of a second different virtual machine on the microkernel; executing a web browser in a third different virtual machine on the microkernel; sending a first message associated with the first user application from the first virtual machine to the third virtual machine using a transfer protocol; generating a first display associated with the first message via a user interface in the web browser; sending a second different message associated with the second user application from the second virtual machine to the third virtual machine using the transfer protocol; and generating a second display associated with the second message via the user interface in the web browser.