Fancy booting your Raspberry Pi into good old BBC BASIC?
RISC OS Open have released RISC OS Pico, a cut-down version of their Raspberry Pi product which does just that.
Free download at https://www.riscosopen.org/content/sales/risc-os-pico
The download link is currently buried in the text, so here it is again:
http://packages.riscosopen.org/RISC-OS_Pico.zip