The R type system

This is a good summary; I could have done with it back in 2006 when I needed to use R for something.

As an aside; while R is a neat tool and pretty powerful in many ways, there's a phrase in the documentation which makes it really clear that it wasn't written by computer scientists: the authors claim that R is 'the same language' as S because it has the same syntax, but it has 'a different engine', by which they mean that it has different semantics...

R, while an excellent toolkit in many ways, suffers somewhat from a deficiency of useful programming tutorials. It's not as though I'm new to that style of data manipulation—I loved APL when I was younger—but almost all R documentation out in the wild is either "how to do some elementary statistical thing" or "reference", with little in between. "R in a Nutshell" is the best I've found so far at filling in the gaps that exist in my knowledge.

Thought it was about the old R-type game's ship system.. ;)