Hi,
I fell some days ago onto a tool called HPUserEdit. Despite being in Spanish at first install, it can be put in most common languages, and it is a very useful tool for UserRPL programming. It allows even to create libraries, embeds the latest emulator (to which you can send the libraries just written), and is freeware.
I imagine that the lack of comments is due to some other tool being even better. In that case, which one?
Here is the link to the programmer website (you can find it as well on HPcalc.org website - an endorsement in itself