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+---
+language: brainfuck
+contributors:
+    - ["Prajit Ramachandran", "http://prajitr.github.io/"]
+    - ["Mathias Bynens", "http://mathiasbynens.be/"]
+---
+
+Brainfuck (not capitalized except at the start of a sentence) is an extremely
+minimal Turing-complete programming language with just 8 commands.
+
+```
+Any character not "><+-.,[]" (excluding quotation marks) is ignored.
+
+Brainfuck is represented by an array with 30,000 cells initialized to zero
+and a data pointer pointing at the current cell.
+
+There are eight commands:
++ : Increments the value at the current cell by one.
+- : Decrements the value at the current cell by one.
+> : Moves the data pointer to the next cell (cell on the right).
+< : Moves the data pointer to the previous cell (cell on the left).
+. : Prints the ASCII value at the current cell (i.e. 65 = 'A').
+, : Reads a single input character into the current cell.
+[ : If the value at the current cell is zero, skips to the corresponding ] .
+    Otherwise, move to the next instruction.
+] : If the value at the current cell is zero, move to the next instruction.
+    Otherwise, move backwards in the instructions to the corresponding [ .
+
+[ and ] form a while loop. Obviously, they must be balanced.
+
+Let's look at some basic brainfuck programs.
+
+++++++ [ > ++++++++++ < - ] > +++++ .
+
+This program prints out the letter 'A'. First, it increments cell #1 to 6.
+Cell #1 will be used for looping. Then, it enters the loop ([) and moves
+to cell #2. It increments cell #2 10 times, moves back to cell #1, and
+decrements cell #1. This loop happens 6 times (it takes 6 decrements for
+cell #1 to reach 0, at which point it skips to the corresponding ] and
+continues on).
+
+At this point, we're on cell #1, which has a value of 0, while cell #2 has a
+value of 60. We move on cell #2, increment 5 times, for a value of 65, and then
+print cell #2's value. 65 is 'A' in ASCII, so 'A' is printed to the terminal.
+
+
+, [ > + < - ] > .
+
+This program reads a character from the user input and copies the character into
+cell #1. Then we start a loop. Move to cell #2, increment the value at cell #2,
+move back to cell #1, and decrement the value at cell #1. This continues on
+until cell #1 is 0, and cell #2 holds cell #1's old value. Because we're on
+cell #1 at the end of the loop, move to cell #2, and then print out the value
+in ASCII.
+
+Also keep in mind that the spaces are purely for readability purposes. You
+could just as easily write it as:
+
+,[>+<-]>.
+
+Try and figure out what this program does:
+
+,>,< [ > [ >+ >+ << -] >> [- << + >>] <<< -] >>
+
+This program takes two numbers for input, and multiplies them.
+
+The gist is it first reads in two inputs. Then it starts the outer loop,
+conditioned on cell #1. Then it moves to cell #2, and starts the inner
+loop conditioned on cell #2, incrementing cell #3. However, there comes a
+problem: At the end of the inner loop, cell #2 is zero. In that case,
+inner loop won't work anymore since next time. To solve this problem,
+we also increment cell #4, and then recopy cell #4 into cell #2.
+Then cell #3 is the result.
+```
+
+And that's brainfuck. Not that hard, eh? For fun, you can write your own
+brainfuck programs, or you can write a brainfuck interpreter in another
+language. The interpreter is fairly simple to implement, but if you're a
+masochist, try writing a brainfuck interpreter… in brainfuck.