Wildly OT: pop-up virtual keyboard for Mac or Linux?

[Rustom Mody]

On Wednesday, February 11, 2015 at 9:50:15 AM UTC+5:30, Chris Angelico wrote:
> On Wed, Feb 11, 2015 at 3:10 PM, Steven D'Aprano wrote:
> > Rustom Mody wrote:
> >
> >> $ setxkbmap -query        # examine current settings
> >
> > Alas, that does not appear to work in Debian squeeze:
> >
> > steve at runes:~$ setxkbmap -query
> > Error!   Option "-query" not recognized
> >
> > Or Centos.
> >
> > What are you using?
> 
> Works for me on Debian Wheezy. Either it's a version difference (I
> don't have any Squeeze machines any more, we're all on Wheezy or
> Jessie), or there's some additional package that I have installed
> here.

This xkb stuff seems to be (surprisingly) in development -- if only the
docs kept pace!

eg My impression is that ubuntus prior to 11.x did not have apl keyboard
Somewhere around 11/12 or after this works

setxkbmap -layout "us,apl" -option "grp:switch"
after that
abcdefghijklmnopqrstuvwxyz
produces
⍺⊥∩⌊∊_∇∆⍳∘'⎕|⊤○*?⍴⌈~↓∪⍵⊃↑⊂
when chorded with R-Alt

If that looks gibberish see that keyboard:
http://xahlee.info/kbd/creating_apl_keyboard_layout.html

Replace the 'apl' in the setxkb by 'gr'
and you will see more familiar territory
αβψδεφγηιξκλμνοπ;ρστθωςχυζ
ΑΒΨΔΕΦΓΗΙΞΚΛΜΝΟΠ:ΡΣΤΘΣΧΥΖ

Of course for it to work the alternate should be working.
eg right now on my box:

$ setxkbmap -query
rules:      evdev
model:      pc104
layout:     us,gr
options:    grp:switch,compose:menu

which shows gr as alternate
and the grp:switch (whatever that means)