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+TODO: sequences, control flow, macros, objects, modules
+
+---
+language: racket
+author: Th3rac25
+---
+
+Racket is a general purpose, multi-paradigm programming language in the Lisp/Scheme family. 
+
+Feedback would be highly appreciated! You can reach me at [@th3rac25](http://twitter.com/th3rac25) or th3rac25 [at] [google's email service]
+
+
+```racket
+; Single line comments start with a semicolon
+#| Multiline strings can be written
+    using three "'s, and are often used
+    as comments
+|#
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; 1. Primitive Datatypes and Operators
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+; You have numbers
+1       
+9999999999999999999999 ; big integers
+3.14
+6.02e+23
+1/2  ; rationals   
+1+2i ; complex numbers   
+
+; Math is what you would expect
+(+ 1 1)  ; => 2
+(- 8 1)  ; => 7
+(* 10 2) ; => 20
+(quotient 5 2) ; => 2
+(remainder 5 2) ; => 1
+(/ 35 5) ; => 7
+(/ 1 3) ; => 1/3
+(exact->inexact 1/3) ; => 0.3333333333333333
+(+ 1+2i  2-3i) ; => 3-1i
+
+; Booleans 
+#t ; for true  
+#f ; for false
+(not #t) ; => #f
+; In conditionals, all non-#f values are treated as true
+
+; Equality for numbers is =
+(= 1 1.0) ; => #t
+(= 2 1) ; => #f
+
+; Characters 
+#\A ; => #\A
+#\λ ; => #\λ 
+#\u03BB ; => #\λ
+
+; Strings are fixed-length array of characters.
+"Hello, world!"
+"Benjamin \"Bugsy\" Siegel" ; backslash is an escaping character
+"λx:(μα.α→α).xx" ; any Unicode character can appear in a string constant
+
+; Strings can be added too!
+(string-append "Hello " "world!") ; => "Hello world!"
+
+; A string can be treated like a list of characters
+(string-ref "Apple" 0) ; => #\A
+
+; format can be used to format strings:
+(format "~a can be ~a" "strings" "formatted")
+
+; Printing is pretty easy
+(printf "I'm Racket. Nice to meet you!\n")
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; 2. Variables and Collections
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+; You need to declare variables before assigning to them.
+; a variable name can use any characters except: () [] {} " , ' ` ; # | \
+(define some-var 5)
+some-var ; => 5
+
+; use set! to reassign
+(set! some-var 6) 
+some-var ; => 6
+
+; Accessing a previously unassigned variable is an exception
+x ; => x: undefined ...
+
+; if can be used as an expression
+
+some_var = a if a > b else b
+; If a is greater than b, then a is assigned to some_var.
+; Otherwise b is assigned to some_var.
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; 3. Collections and Sequences
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+; Lists are linked-list data structures, vectors are fixed-length arrays.
+'(1 2 3) ; a list
+#(1 2 3) ; a vector
+
+; Use cons to add an item to the beginning of a list
+(cons 4 '(1 2 3)) ; => (4 1 2 3)
+
+; Use append to add lists together
+(append '(1 2) '(3 4)) ; => (1 2 3 4)
+
+; Use filter, map to interact with collections
+(map add1 '(1 2 3)) ; => (2 3 4)
+(filter even?  '(1 2 3)) ; => (2)
+
+; Use fold to reduce them
+(foldl + 0 '(1 2 3 4))
+; = (+ 1 (+ 2 (+ 3 (+ 4 0)))
+; => 10
+
+; a sequence is an ordered collection of value
+(sequence? '(1 2 3)) ; => #t
+(sequence? #(1 2 3)) ; => #t
+
+;; more sequence stuff here !
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; 3. Functions
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+; Use fn to create new functions. A function always returns
+; its last statement.
+(lambda () "Hello World") ; => #<procedure>
+
+; (You need extra parens to call it)
+((lambda () "Hello World")) ; => "Hello World"
+
+; You can create a variable using define
+(define x 1)
+x ; => 1
+
+; Assign a function to a var
+(define hello-world (lambda () "Hello World"))
+(hello-world) ; => "Hello World"
+
+; You can shorten this to:
+(define (hello-world) "Hello World")
+
+; The () is the list of arguments for the function.
+(define hello 
+  (lambda (name)
+    (string-append "Hello " name)))
+(hello "Steve") ; => "Hello Steve"
+
+; You can have multi-variadic functions, too
+(define hello2
+  (case-lambda 
+    [() "Hello World"]
+    [(name) (string-append "Hello " name)]))
+(hello2 "Jake") ; => "Hello Jake"
+(hello2) ; => "Hello World"
+
+; Functions can pack extra arguments up in a list
+(define (count-args . args)
+  (format "You passed ~a args: ~a" (length args) args))
+(count-args 1 2 3) ; => "You passed 3 args: (1 2 3)"
+
+; You can mix regular and packed arguments
+(define (hello-count name . args)
+  (format "Hello ~a, you passed ~a extra args" name (length args)))
+(hello-count "Finn" 1 2 3)
+; => "Hello Finn, you passed 3 extra args"
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; 4. Control Flow
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; 5. Modules
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; 6. Classes
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; 7. Macros
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+
+```
+
+;; Further Reading
+
+Still up for more? Try [Quick: An Introduction to Racket with Pictures](http://docs.racket-lang.org/quick/)
+