"Is there a file or tutorial someone would point me toward that that explains the differences between LPmud and Smaug?(or Circle, Rom, etc) "
I'm not that familiar with Diku derivatives, so I
can only give you a general idea of the differences
as I understand them.
The simplest comparison is:
Diku derivatives are games that run from compiled
code. LP muds have a binary program that is executable,
compiled code, but the game world is not part of that
compiled code. The game world is composed of files
interpreted by the program, or "driver", on the fly.
The files are in a scripting/programming format
called LPC. A discussion of the ramifications of
this is at http://lpmuds.net/lp_versus_diku.html
"(I've never played anything LPmud-based so I am kind of lost as to what it does and does not do - is combat possible?"
LPmuds can do anything you want.
There is some sort of perception that LPmuds are
somehow not combat oriented. You're not the first
person to ask if you can do combat in LP. In my
mind this is a very, very strange question, because
LPmuds have historically been all about combat
and fighting orcs and questing and whatnot. Sure, some
muds using LPC have been mostly social, but that
is most decidedly not the preponderant tradition.
LP tradition is gaming, with RP aspects being
normal and possible, but not normally the focus.
Having said that, it's trivially easy to set up an LP
mud that's mostly RP and little combat since, as
I said, LPmuds can do anything you want.
I think that the reason people have got the idea that
LP isn't combat oriented is that LP muds might get
lumped in with MOOs and MUSHes, types of muds that
often use an interpreted scripting/programming language
as well. This is fair in that MOOs and MUSHes provide
environments that allow some classes of players to
modify the game on the fly using a local language.
It's unfair though, in that MOOs and MUSHes typically
do not focus on combat, and LP muds typically do.
"if you were coding a mud why would you pick LPmud over other codebases?"
Some reasons you'd go with LP:
*) You already know LPC and are used to LPmuds.
*) You want to make a very customized mud, but do not
want to invest years in learning enough C to do it.
"Or why would you not pick it?"
Some reasons you'd avoid LP:
*) You are proficient with C and like Diku derivatives.
*) You want to run a commercial mud.
*) LPC is way simpler than C, but still involves some
effort to learn. For some, that's a turnoff.
"if the latter, what base would you choose and why?"
Depends on your plans. If you're planning on being
a C coder at some point, then you might as well
go with a Diku derivative. Otherwise, I'd strongly
recommend Coffeemud, which is a fine, fine codebase
that more people should give a day in court.
PS Shameless plug:
I'm the maintainer of Dead Souls and recommend it
for new mud admins. It's powerful enough for LP heroes,
but also specifically geared to be easy to pick up
for newbs. You can pick up Dead Souls here: http://dead-souls.net/
(the version on Sourceforge
is old and not recommended).
There are other LP mudlibs available as well. You
have your pick of relatively easy ones to install