Rebol: Demo

The following script is a demo showing all Rebol capabilities, with few lines of code (half a page). Nick Antonaccio wrote this script and condensed all in a very obfuscated way:
 REBOL[

File: %demo.r

Date: 3-sep-2009

Title: "Demo"

Author: Nick Antonaccio

Purpose: {

Amazingly small REBOL demo app: 10 useful programs in only 2.5k

(LESS THAN HALF A PRINTED PAGE OF CODE!):

1 - FREEHAND PAINT: draw and save graphic images

2 - SNAKE GAME: eat food, avoid hitting the walls and yourself 

3 - TILE PUZZLE, "15": arrange the tiles into alphabetical order

4 - CALENDAR: save and view events for any date

5 - VIDEO: live webcam video viewer - not just static images

6 - IPs: display your LAN and WAN IP addresses

7 - EMAIL: read emails from any pop account

8 - COUNT DAYS: count the days between 2 selected dates

9 - PLAY SOUNDS: Browse your computer for wave files to play

10 - FTP TOOL: web site editor (browse folders on your server,

click files to edit and save changes back to the server,

create and edit new files etc.)

This example is 100% native REBOL. No external libraries, images,

GUI components, or other resources of any kind are imported. It runs

on Windows, Mac, Linux, and any other OS supported by REBOL/View.

Taken from the tutorial at http://re-bol.com/rebol.html

}

]

p: :append kk: :pick r: :random y: :layout q: 'image

z: :if gg: :to-image v: :length? g: :view k: :center-face ts: :to-string

tu: :to-url sh: :show al: :alert rr: :request-date co: :copy g y[style h

btn 150 h"Paint"[g/new k y[s: area black 650x350 feel[engage: func[f a e][

z a = 'over[p pk: s/effect/draw e/offset sh s]z a = 'up[p pk 'line]]]

effect[draw[line]]b: btn"Save" [ save/png %a.png gg s al"Saved 'a.png'"]btn

"Clear" [ s/effect/draw: co[line]sh s]]]h"Game" [ u: :reduce x: does[al join{

SCORE: }[v b]unview]s: gg y/tight[btn red 10x10]o: gg y/tight[btn tan

10x10]d: 0x10 w: 0 r/seed now b: u[q o(((r 19x19)* 10)+ 50x50)q s(((r

19x19)* 10)+ 50x50)]g/new k y/tight[c: area 305x305 effect[draw b]rate 15

feel[engage: func[f a e][z a = 'key [d: select u['up 0x-10 'down 0x10 'left

-10x0 'right 10x0]e/key]z a = 'time[z any[b/6/1 < 0 b/6/2 < 0 b/6/1 > 290

b/6/2 > 290][x]z find(at b 7)b/6[x]z within? b/6 b/3 10x10[p b u[q s(last

b)]w: 1 b/3:((r 29x29)* 10)]n: co/part b 5 p n(b/6 + d)for i 7(v b)1[

either(type?(kk b i)= pair!)[p n kk b(i - 3)][p n kk b i]]z w = 1 [ clear(

back tail n)p n(last b)w: 0]b: co n sh c]]]do [focus c]]]h"Puzzle"[al{

Arrange tiles alphabetically:}g/new k y[origin 0x0 space 0x0 across style

p button 60x60[z not find [ 0x60 60x0 0x-60 -60x0]face/offset - x/offset[

exit]tp: face/offset face/offset: x/offset x/offset: tp]p"O"p"N"p"M"p"L"

return p"K"p"J"p"I"p"H"return p"G"p"F"p"E"p"D"return p"C"p"B"p"A"x: p

white edge[size: 0]]]h"Calendar" [do bx:[z not(exists? %s)[write %s ""]rq:

rr g/new k y[h5 ts rq aa: area ts select to-block(find/last(to-block read

%s)rq)rq btn"Save" [write/append %s rejoin[rq" {"aa/text"} "]unview do bx]]

]]h"Video" [wl: tu request-text/title/default"URL:"join"http://cam.luzern.org/axis-cgi/jpg/image.cgi?resolution="

"640x480"g/new k y[image load wl 640x480 rate 0 feel[engage: func[f a e][

z a = 'time [ f/image: load wl show f]]]]]h"IPs" [ parse read tu join"http://"

"guitarz.org/ip.cgi"[thru]i: last parse my none

al ts rejoin  [ "WAN: "i" -- LAN: "read join dns:// read dns://]]h"Email"[

g/new k y[mp: field"pop://user:pass@site.com"btn"Read" [ma: co[]foreach i

read tu mp/text[p ma join i"^/^/^/^/^/^/"editor ma]]]]h"Days"[g/new k y[

btn"Start" [ sd: rr]btn"End" [ed: rr db/text: ts(ed - sd)show db]text{Days

Between:}db: field]]h"Sounds" [ps: func[sl][wait 0 rg: load sl wf: 1 sp:

open sound:// insert sp rg wait sp close sp wf: 0]wf: 0 change-dir

%/c/Windows/media do wl: [ wv: co[]foreach i read %.[z %.wav = suffix? i[p

wv i]]]g/new k y[ft: text-list data wv[z wf <> 1[z error? try[ps value][al

"Error"close sp wf: 0]]]btn"Dir" [ change-dir request-dir do wl ft/data: wv

sh ft]]]h{FTP}[g/new k y[px: field"ftp://user:pass@site.com/folder/"[

either dir? tu va: value[f/data: sort read tu va sh f][editor tu va]]f:

text-list[editor tu join px/text value]btn"?"[al{Type a URL path to browse

(nonexistent files are created). Click files to edit.}]]]]