@9214 pointed you to Linux GTK builds of Red. My example was tested in macOS so haven't tried it on Linux but you'll need GTK & 32bit compatibility libraries installed for it to work.

Rebol/View as always worked on Linux though you will also need 32bit compat + Freetype libraries - https://stackoverflow.com/questions/34524169/rebol-2-stopped...

And there's a 64-bit Rebol 3 with R3-GUI from Atronix, which should only need Freetype library installed - https://www.atronixengineering.com/downloads

The VID has changed a little bit over time. Here's the example in Rebol2 View...

    Rebol []

    view layout compose [
        across
        text (rejoin [{The sum of } figs: [1 2 3 4] { is: }])
        answer: text {......}
        return
        button "Push me to calculate" 200x20 [
            answer/text: to-string sum figs
            show answer
        ]   
    ] 

And here it is in Rebol 3 / R3-GUI...

    load-gui

    view compose [
        hgroup [
            text (rejoin [{The sum of } figs: [1 2 3 4] { is: }])
            answer: text {......}
            return
            button "Push me to calculate" on-click [
                set-face answer to-string sum figs
            ]
        ]
    ]

Both scripts above worked fine on my Ubuntu 18 Linux.

NB. Rebol doesn't come with a SUM function so here's one defined...

    sum: func [s /local total] [
        total: 0
        forall s [total: total + s/1]
        total
    ]

That's not true.

https://www.reddit.com/r/redlang/comments/dzobh0/latest_gtk_...