Instructions for installing the latest version of GNU APL on Debian/Ubuntu Linux machines with Finnish keyboard layout:
(Updated 2013.11.13)
======

Run the following commands inside your terminal. If you don't have "sudo" then use regular root account to run the sudo commands.

$ sudo apt-get install build-essential dpkg-dev subversion wget
$ sudo apt-get install debhelper autotools-dev liblapack-dev libgl1-mesa-glx mime-support libreadline5 locales libc6 libgfortran3 libasound2 libatlas3gf-base gawk # current reqs as of 2013.11.12
$ mkdir -p ~/build/apl
$ cd ~/build/apl
$ svn co http://svn.savannah.gnu.org/svn/apl/trunk
$ cd trunk
$ dpkg-checkbuilddeps
$ sudo apt-get install "any missing packages listed by dpkg-checkbuilddeps"
$ ./configure
$ make DEB
$ sudo dpkg -i ftp-upload/apl*.deb # "make install" might also do the same, but then GNU APL might not be registered with Debian/Ubuntu package managers. I haven't read the Makefile. 

$ wget http://oksman.eu/apl/dotXmodmap_fin
$ cat dotXmodmap_fin >> ~/.Xmodmap
$ xmodmap ~/.Xmodmap
# If you get errors like: "bad keysym name 'ezh' in keysym list" on old Debian/Ubuntu machines, then edit ~/.Xmodmap and replace "ezh" → "z" and "EZH" → "Z".
# You can alternatively download http://oksman.eu/apl/dotXmodmap_fin_noEZH which contains the modifications.

$ apl

Now "1+2" and Return should produce output "3".

Have fun with APL and visit Dr. Jürgen Sauermann's GNU APL home page at https://www.gnu.org/software/apl/ for the latest news.

Best wishes,
Miika

---

If you have trouble seeing the special APL characters, then you need to use an Unicode compliant terminal emulator with a font
that contains APL unicode characters. Rxvt-unicode as terminal with GNU Unifont works for me;
"sudo apt-get install rxvt-unicode-256color ttf-unifont".

You can use "xmodmap ~/.Xmodmap" to load the keyboard layout if your session manager doesn't do that automatically when you login
to your desktop. The APL layout uses "kotoistus" Finnish keyboard layout XkbVariant as its base. For a graphical variant for
choosing the keyboard layout, see the post by David B. Lamkins at https://lists.gnu.org/archive/html/bug-apl/2013-11/msg00000.html
Note also that you can now type APL characters into almost any other program like Vim or Emacs editor. Nice for scripting APL.

You can for example use "]XTERM OFF" command inside the APL interpreter if you can't see black output text. You could also change
your terminal background color or modify GNU APL's source code. Probably a better alternative is to read "$ info apl 'Chapter 1'"
section "Config File for GNU APL" and uncomment the color sequences for dark background in GNU APL's preferences file.
"$ mkdir ~/.gnu-apl", "cp ~/build/apl/trunk/gnu-apl.d/preferences ~/.gnu-apl/", edit ~/.gnu-apl/preferences and uncomment lines:
CIN-SEQUENCE           1b 5b 30 3b 33 32 3b 34 30 6d    // ESC [0;32;40m
COUT-SEQUENCE          1b 5b 30 3b 33 37 3b 34 30 6d    // ESC [0;37;40m
CERR-SEQUENCE          1b 5b 30 3b 33 31 3b 34 30 6d    // ESC [0;31;40m
RESET-SEQUENCE         1b 5b 30 3b 33 37 3b 34 30 6d    // ESC [0;37;48m

A nice lynx-like info page browser named pinfo is available from http://pinfo.sourceforge.net/ or "$ sudo apt-get install pinfo".
See "$ man pinfo" for help after installing it. You can use commands like "$ pinfo apl" and "pinfo '(apl)Chapter 1'".

")OFF" inside the APL interpreter exits the session.

GNU APL also has support for .apl script files - read more about it in "$ info apl 'Chapter 2'" section "APL Scripting".

If you can't compile libreadline support into GNU APL and want to use for example up arrow to go back in command history, then
ledit line editor from http://cristal.inria.fr/~ddr/ledit/ might help. "$ sudo apt-get install ledit" and invoke GNU APL with
"$ ledit -u apl". See "$ man ledit" for more information concerning ledit, like support for command history searches.

Here's the Finnish APL keyboard layout with Menu-key functioning as mode_switch for APL characters. Menu+Shift produces the
alternate APL chars. This is based on GNU APL's "README-3-keyboard". Shift+Menu in that order sends the original Menu message
to X11 if you need it for something else.

╔════╦════╦════╦════╦════╦════╦════╦════╦════╦════╦════╦════╦════╦═════════╗
║ ½⍨ ║ !¡ ║ "€ ║ #£ ║ ¤⍧ ║ %  ║ &  ║ /  ║ (⍂ ║ )⍱ ║ =⍲ ║ ?≡ ║ `⌹ ║         ║
║ §◊ ║ 1¨ ║ 2¯ ║ 3< ║ 4≤ ║ 5= ║ 6≥ ║ 7> ║ 8≠ ║ 9∨ ║ 0∧ ║ +× ║ ´÷ ║ BACKSP  ║
╠════╩══╦═╩══╦═╩══╦═╩══╦═╩══╦═╩══╦═╩══╦═╩══╦═╩══╦═╩══╦═╩══╦═╩══╦═╩══╦══════╣
║       ║ Q¿ ║ W⌽ ║ E⍷ ║ R  ║ T⍉ ║ Y¥ ║ U  ║ I⍸ ║ O⍥ ║ P⍟ ║ Å  ║ ^  ║  *⍀  ║
║  TAB  ║ q? ║ w⍵ ║ e∈ ║ r⍴ ║ t∼ ║ y↑ ║ u↓ ║ i⍳ ║ o○ ║ p⋆ ║ å← ║ :→ ║  '⍝  ║
╠═══════╩═╦══╩═╦══╩═╦══╩═╦══╩═╦══╩═╦══╩═╦══╩═╦══╩═╦══╩═╦══╩═╦══╩═╦══╩══════╣
║ (CAPS   ║ A⊖ ║ S  ║ D  ║ F⍫ ║ G⍒ ║ H⍋ ║ J⍤ ║ K⌺ ║ L⍞ ║ Ö  ║ Ä  ║         ║
║  LOCK)  ║ a⍺ ║ s⌈ ║ d⌊ ║ f_ ║ g∇ ║ h∆ ║ j∘ ║ k' ║ l⎕ ║ ö⊢ ║ ä⊣ ║ RETURN  ║
╠═════════╩═══╦╩═══╦╩═══╦╩═══╦╩═══╦╩═══╦╩═══╦╩═══╦╩═══╦╩═══╦╩═══╦╩═════════╣
║             ║ Z  ║ X  ║ C⍝ ║ V  ║ B⍎ ║ N⍕ ║ M⌶ ║ ;⍪ ║ :⍙ ║ _⌿ ║          ║
║  SHIFT      ║ z⊂ ║ x⊃ ║ c∩ ║ v∪ ║ b⊥ ║ n⊤ ║ m| ║ ,⌷ ║ .⍎ ║ -⍕ ║  SHIFT   ║
╚═════════════╩════╩════╩════╩════╩════╩════╩════╩════╩════╩════╩══════════╝

Here's the dotXmodmap_fin for reference:
<---dotXmodmap_fin begins--->
keycode 135 = Mode_switch Menu Mode_switch Menu Mode_switch Mode_switch
keycode  10 = 1 exclam U00A8 U00A1 NoSymbol exclamdown NoSymbol exclamdown 1 exclam NoSymbol exclamdown 1 exclam NoSymbol exclamdown
keycode  11 = 2 quotedbl U00AF U20AC at rightdoublequotemark at rightdoublequotemark 2 quotedbl at rightdoublequotemark 2 quotedbl at rightdoublequotemark
keycode  12 = 3 numbersign less U00A3 sterling guillemotright sterling guillemotright 3 numbersign sterling guillemotright 3 numbersign sterling guillemotright
keycode  13 = 4 currency U2264 U2367 dollar guillemotleft dollar guillemotleft 4 currency dollar guillemotleft 4 currency dollar guillemotleft
keycode  14 = 5 percent equal percent U2030 leftdoublequotemark U2030 leftdoublequotemark 5 percent U2030 leftdoublequotemark 5 percent U2030 leftdoublequotemark
keycode  15 = 6 ampersand U2265 ampersand singlelowquotemark doublelowquotemark singlelowquotemark doublelowquotemark 6 ampersand singlelowquotemark doublelowquotemark 6 ampersand singlelowquotemark doublelowquotemark
keycode  16 = 7 slash greater slash braceleft NoSymbol braceleft NoSymbol 7 slash braceleft NoSymbol 7 slash braceleft
keycode  17 = 8 parenleft U2260 U2342 bracketleft less bracketleft less 8 parenleft bracketleft less 8 parenleft bracketleft less
keycode  18 = 9 parenright U2228 U2371 bracketright greater bracketright greater 9 parenright bracketright greater 9 parenright bracketright greater
keycode  19 = 0 equal U2227 U2372 braceright degree braceright degree 0 equal braceright degree 0 equal braceright degree
keycode  20 = plus question U00D7 U2261 backslash questiondown backslash questiondown plus question backslash questiondown plus question backslash questiondown
keycode  21 = dead_acute dead_grave U00F7 U2339 dead_cedilla dead_ogonek dead_cedilla dead_ogonek dead_acute dead_grave dead_cedilla dead_ogonek dead_acute dead_grave dead_cedilla dead_ogonek
keycode  24 = q Q question U00BF q Q q Q q Q q Q q Q q Q
keycode  25 = w W U2375 U233D w W w W w W w W w W w W
keycode  26 = e E U2208 U22F8 EuroSign NoSymbol EuroSign NoSymbol e E EuroSign NoSymbol e E EuroSign
keycode  27 = r R U2374 R r R r R r R r R r R r R
keycode  28 = t T U223C U2349 thorn THORN thorn THORN t T thorn THORN t T thorn THORN
keycode  29 = y Y U2191 U00A5 y Y y Y y Y y Y y Y y Y
keycode  30 = u U U2193 U u U u U u U u U u U u U
keycode  31 = i I U2373 U2378 idotless bar idotless bar i I idotless bar i I idotless bar
keycode  32 = o O U25CB U2365 oe OE oe OE o O oe OE o O oe OE
keycode  33 = p P U22C6 U235F dead_horn dead_hook dead_horn dead_hook p P dead_horn dead_hook p P dead_horn dead_hook
keycode  34 = aring Aring U2190 Aring dead_doubleacute dead_abovering dead_doubleacute dead_abovering aring Aring dead_doubleacute dead_abovering aring Aring dead_doubleacute dead_abovering
keycode  35 = dead_diaeresis dead_circumflex U2192 U236C dead_tilde dead_macron dead_tilde dead_macron dead_diaeresis dead_circumflex dead_tilde dead_macron dead_diaeresis dead_circumflex dead_tilde dead_macron
keycode  38 = a A U237A U2296 schwa SCHWA schwa SCHWA a A schwa SCHWA a A schwa SCHWA
keycode  39 = s S U2308 S ssharp NoSymbol ssharp NoSymbol s S ssharp NoSymbol s S ssharp
keycode  40 = d D U230A D eth ETH eth ETH d D eth ETH d D eth ETH
keycode  41 = f F underscore U236B f F f F f F f F f F f F
keycode  42 = g G U2207 U2352 g G g G g G g G g G g G
keycode  43 = h H U2206 U234B h H h H h H h H h H h H
keycode  44 = j J U2218 U2364 j J j J j J j J j J j J
keycode  45 = k K apostrophe U233B kra NoSymbol kra NoSymbol k K kra NoSymbol k K kra
keycode  46 = l L U2395 U235E dead_stroke NoSymbol dead_stroke NoSymbol l L dead_stroke NoSymbol l L dead_stroke
keycode  47 = odiaeresis Odiaeresis U22A2 Odiaeresis oslash Oslash oslash Oslash odiaeresis Odiaeresis oslash Oslash odiaeresis Odiaeresis oslash Oslash
keycode  48 = adiaeresis Adiaeresis U22A3 Adiaeresis ae AE ae AE adiaeresis Adiaeresis ae AE adiaeresis Adiaeresis ae AE
keycode  49 = section onehalf U25CA U2368 dead_stroke NoSymbol dead_stroke NoSymbol section onehalf dead_stroke NoSymbol section onehalf dead_stroke
keycode  51 = apostrophe asterisk U235D U2340 dead_caron dead_breve dead_caron dead_breve apostrophe asterisk dead_caron dead_breve apostrophe asterisk dead_caron dead_breve
keycode  52 = z Z U2282 Z ezh EZH ezh EZH z Z ezh EZH z Z ezh EZH
keycode  53 = x X U2283 X multiply periodcentered multiply periodcentered x X multiply periodcentered x X multiply periodcentered
keycode  54 = c C U2229 U235D U2500 C U2500 C c C
keycode  55 = v V U222A V asciicircum V asciicircum
keycode  56 = b B U22A5 U234E b B b B b B b B b B b B
keycode  57 = n N U22A4 U2355 eng ENG eng ENG n N eng ENG n N eng ENG
keycode  58 = m M U2223 U2336 mu emdash mu emdash m M mu emdash m M mu emdash
keycode  59 = comma semicolon U2337 U236A rightsinglequotemark leftsinglequotemark rightsinglequotemark leftsinglequotemark comma semicolon rightsinglequotemark leftsinglequotemark comma semicolon rightsinglequotemark leftsinglequotemark
keycode  60 = period colon U234E U2359 dead_belowdot dead_abovedot dead_belowdot dead_abovedot period colon dead_belowdot dead_abovedot period colon dead_belowdot dead_abovedot
keycode  61 = minus underscore U2355 U233F endash dead_belowcomma endash dead_belowcomma minus underscore endash dead_belowcomma minus underscore endash dead_belowcomma
<---dotXmodmap_fin ends--->