This beta release adds multicore support for the Raspberry Pi Pico and other supported RP2040 boards, which includes functioning multitasking on both cores simultaneously. It should be noted that each core functions largely independently aside from sharing RAM and flash, with interaction between cores being mediated through hardware spinlocks and FIFO's (mailboxes); the two multitasking environments for the two cores must not interact with one another, and attempting to do so will result in an undefined state. There are some limitations so far, such as that interrupt-driven serial IO must be disabled before booting the second core, and that once the second core has been booted, the MCU must be power-cycled, and not merely rebooted, or otherwise, prior to writing to flash or otherwise the MCU will crash; this is why I am making this a beta release and not a normal release.