try crystal

Type Crystal. It runs. It answers.

Lesson 1 of 3
Lesson

Lesson 1 of 3. Start by saying hello. puts writes a line of output, and it is about to give you your first answer from the machine.

The line
puts "Hello, Crystal!"

Stuck? puts prints whatever follows it, on a line of its own. The double quotes make the words a String, and the capital letters count: the compiler is polite about many things, spelling is not one of them.

EditorCmd or Ctrl + Enter
Output
This is real Crystal, running for real. No signup, no setup, three short lessons. Whatever you write in the editor goes to a sandbox, gets compiled and run by the actual toolchain, and answers back here. Write the line from the lesson on the left, then press Run.