In the foreground is an ArmBook (i.e. Pinebook) running RISC OS 5.27, from RComp. Behind it is an LG Flatron IPS235 monitor displaying output from RISC OS 5.24 running on a Raspberry Pi 3B+, which sits in the green case, with a red LED shining out.
Just behind the Pinebook is a Logitech K260 keyboard, with its accompanying mouse, running wirelessly from a little USB stick. The flat white object next to it at the left is a Sonnics 256Gb ADFS hard-drive attached via USB.
At the left, keeping shyly out of the picture because it is not part of the RISC OS scene, you may see the corner of a BENQ GL2250 monitor displaying output from a Raspberry Pi 4 running Raspbian Buster, housed in the official Raspberry pink casing, cooled by Pimoroni's fan-shim. In front is a dwarf Rii keyboard and mouse, sitting on a Moomintroll mousepad, communicating with a USB micro-dongle, not visible in the picture. The Rii does not work with RISC OS, alas which is why the trusty old K260 has to be used with the Raspberry Pi running RISC OS.
The Pinebook runs Manjaro Linux when the SD card containing RISC OS 5.27 is removed. Manjaro looks gorgeous but I am still too ignorant to exploit it.
There appear to be one or two issues still to be sorted with RISC OS 5.27. The screen redraw leaves some lines of pixels behind, but that might be down to my toolsprites having not quite the right size. Dragging objects from Paint and Draw Windows causes those applications to crash.
Other Computer setups
If you want to add yours, send us send a pic and an intro on your RISC OS related setup (email to markstephens At idrsolutions.com), and we will add it.