And besides general craziness and DSLs as pointed above, you can also easily experiment with relatively complex language-level constructs, like derived attribut

And besides general craziness and DSLs as pointed above, you can also easily experiment with relatively complex language-level constructs, like derived attributes or cacheable functions [talked a bit about it here https://news.ycombinator.com/item?id=22338923 https://news.ycombinator.com/item?id=22338923]. Trying to make such experiments safe in Ruby would be unwise, but starting them in Ruby is happiness.