brainfuck_fact.b

#! /usr/local/bin/brainfuck
++++++++++[>+++++++>++++++++++>++++++>+<<<<-]>++.>+.+++++++..+++.>+.<<+++++++++++++++.>.+++.------.--------.>>.

brainfuck_fact_commented.b

+++++ +++++             initialize counter (cell #0) to 10
[                       use loop to set the next four cells to 70/100/60/10
    > +++++ ++              add  7 to cell #1
    > +++++ +++++           add 10 to cell #2 
    > ++++++                add  3 to cell #3
    > +                     add  1 to cell #4
    <<<< -                  decrement counter (cell #0)
]                   
> ++ .                  print 'H'
> + .                   print 'e'
+++++ ++ .              print 'l'
.                       print 'l'
+++ .                   print 'o'
> + .                   print '='
<< +++++ +++++ +++++ .  print 'W'
> .                     print 'o'
+++ .                   print 'r'
----- - .               print 'l'
----- --- .             print 'd'
>> .                     print '\n'

output.txt

root@master:~ # facter hello
World

This uses the interpreter at zacstewart/brainfuck-pp#1

Noooooooooooooo