Calculator
Create a basic or advanced calculator.
Binary Birthday Game
Guess a person's birthday using only 5 binary bits.
Unit Converter
Create a handy tool for converting temperature, weight, time, or distance.
Number Pyramid
Write a program to display a symmetrical pyramid of numbers.
Insertion Sort
Sharpen your skills by coding this simple sorting algorithm.
Coin Toss
Need to flip a coin? Write a program for that!
Tic-Tac-Toe
Here is a shorter description.
Palindrome checker
Enjoy word puzzles? This one might be fun for you!
VIM Adventures
An online game for learning how to use the vim text editor.
Joke Bot
Have some good jokes? Make a bot to tell them! Or, get some jokes from an API.
Flappy Bird
This popular game is always a fun time. Put your own spin on it!
Number Guessing Game
Play this simple game against a friend or the computer.
Cellular Automaton
A fun way to create interesting patterns based on simple rules.
OverTheWire Wargames
Learn and practice hacking/security concepts in the form of fun-filled games.
SQL Murder Mystery
Can you find out whodunnit?
Tower of Hanoi
Code a solver for this famous puzzle using recursion.
Yoda Speak
Translate plain old English into Yoda's way of speaking.
Screeps
MMO sandbox game for programmers
Bubble Sort
Sharpen your skills by coding this simple sorting algorithm.
Hangman (or Snowman)
Put your own spin on this classic word game.
Caesar Cipher
Create encrypted messages using this simple cipher.
Snake
Create your own version of this popular game.
Sudoku Solver
Write a program to solve Sudoku puzzles.
Regex Crossword
A crossword puzzle game, where the crossword clues are defined using regular expressions.
Pong
Create your own version of this popular game.
CSS Diner
Learn and practice CSS selectors in an interactive game.
Dice Roller
Need to roll some dice? Write a program for that!
Chinese Zodiac Calendar
Display each animal sign and tell people which sign they are.
Timer
Create a useful tool for toothbrushing, cooking, and more!
Fibonacci Sequence
This simple number sequence has a lot to offer coders, from simple iteration to recursion and dynamic programming.
md5 cracker
Write a program to decrypt this common hashing algorithm.