Triple quoted strings in Boo are used to preserve spacing and linebreaks without a thick slathering of \n's all over your precious code.
It is good for visually representing XML, for instance:
xml = """
<xml>
<randomElement>
</randomElement>
</xml>
"""
It is also most excellent for formatting console output:
name = prompt("Name: ")
age = prompt("Age: ")
sex = prompt("Sex: ")
print """
Hello, ${name}!
My name is Hal, and I will be your Operating System today.
My sensors indicate that you are a ${age} year old ${sex}
If you need any assistance navigating this user interface, please ask.
...
Humans are so fragile...
"""