The Red programming language is still in the bootstrap phase using a compiler written in Rebol 2. Rebol 2 doesn't run on ARM processors so at the moment programs for ARM computers have to be cross-compiled on an Intel computer.
The Red REPL (known as "console") is simply a Red program that sits on top of the Red runtime. The Red runtime is written in the low-level Red/System dialect and can be cross-complied for Linux running on ARM.
The source of the console program is included in the Red Github Repository. Assuming that a Rebol interpreter is available, cross-compiling the console takes a single terminal command:
rebol -qs red.r -t Linux-ARM runtime/console/console.red
One of the many things that I like about Red is how simple it is to compile for different targets. The output from the compiler looks like this:
-=== Red Compiler 0.4.2 ===-
...compilation time : 395 ms
...compilation time : 20029 ms
...linking time : 245 ms
...output file size : 618544 bytes
...output file : /Users/peter/VMShare/Languages/Red/console
I followed the excellent advice from Milliways on the Raspberry Pi Stack Exchange and installed netatalk on my Pi. I can now connect to my Pi from my MacBook. I simply copied the compiled Red console program over to it using OS X Finder.
Red doesn't have to be installed on the Raspberry Pi, simply type its path on the command line to run it. (The Red compiler even sets the execute bit!)
|Red on Raspberry Pi|
Click to enlarge