x0xlarge is a CPU upgrade for the x0xb0x made by xlarge based on collaborative community input.
The main reason it was developed is because the original cpu has very little room for enhancements. With up to 16x bigger flash memory to store the firmware, the x0xlarge is a future-proof replacement of the original atmega 162.
Original info on yhype x0xlarge page.
Additional info on Anton Savov’s page
Read about an alternative firmware firmware for this cpu board in n0nx0x.
UPDATE 2016: I am now the distributor of x0xlarge cpu boards!
UPDATE 2020: The x0xlarge has been redesigned by Anton Savov and is available to order from my shop.