A system, method and a computer-readable medium for processing resources on a multithreaded browser. The browser includes a main thread and receives a resource. The browser initializes the main thread, the main thread includes an event loop and initializes a plurality of virtual machines, one virtual machine for each code segment within the resource. Each virtual machine includes a UI thread and is configured to share the main thread within the browser with the UI thread. Each UI thread is further configured to execute an event scheduled on the event loop on the virtual machine.