[R] productivity tools in R?

[Michael]

Hi all,

Could anybody point me to some latest productivity tools in R? I am
interested in speeding up my R programming and improving my efficiency
in terms of debugging and developing R programs.

I saw my friend has a R Console window which has automatic syntax
reminder when he types in the first a few letters of R command. And
he's using R under MAC. Is that a MAC thing, or I could do the same on
my PC Windows?

More pointers about using R for efficiency in development are highly
apprecaited!

Thanks a lot!