Easy calculation of probabilities using a computed z-table.
Go does not support tail call optimization, so the trampoline device can be used.
Node.js does not support tail call optimization, but a trampoline has the same effect.
How to use aggregate functions in the framework is not well documented.
Recursion is not an easy concept at first, but once you understand it, it can be really beautiful.
Emacs is a powerful tool not only for programmers that has many special modes and can be easily customized.