The FOURtress is one of the growing stable of machines available from RISCOSbits.

It is an over-clocked RaspberryPi 4 in a very compact (and neat) case. The case itself provides a huge amount of passive cooling, so you really need to work the machine before the fan will need to kick in.
 
The FOURtress comes with both an SD card and SSD drive. While the FOURtress is a very fast and capable RISC OS machine in a very compact and stylish box, the real excitement for me was its Dual boot feature.
 
RISCOSbits have developed some software which lets you boot into Linux from RISC OS and either stay in Linux until you switch back or reboot the box. There is a shared file partition so that you can put shared files in a location where either Linux or RISC OS can see them. You can only run one OS at a time but it is very easy to switch between them.
 
The Linux part is really exciting and the reason I bought this machine. I am comparing it with performance for Browsing and other activities and there is a speed difference to my 2020 MacBook Pro (there should be as the MacBook is over 5 times the price!). But it is not as pronounced as it should be and this is the first Pi I have used where I have felt the Linux is credible for serious work as a Linux machine.
 
A machine as exciting as the FOURtress really deserves a series of articles exploring its capabilities and a lot of testing (that is what I told my wife anyway). But for the moment I am just going to gloat over my new machine...
 
You can also read more about FOURtress running RISC OS and FOURtress as a Linux machine.
 
You can find out more at the FOURtress website