A quick synopsis of my opinions of those I've tried:
* the old HP AdvanceLink (?) and Unison's followup Business Session
  appear to have fallen into the "stale" category, at least HP's
  product which I believe Unison picked up.  If it is still being
  actively enhanced (Session) I retract that comment, but I've not
  seen/heard much from them on this product lately.
* Minisoft is the "economy" emulator which started with rudimentary file
  transfer and scripting, but is getting more robust.  If you just want
  a basic HP terminal emulator, it does the trick.  Last one I tried was
  an early Windows version and it had some GUI/font problems, but I've
  heard current versions are more mature.  Not sure of their Win95/NT
  status.
* Reflection is the "Microsoft" version of an HP emulator.  Started out
  basic, gets fatter with every release.  Rich scripting language which
  was recently replaced[augmented] by a Visual Basic type scripting
  language which can talk to VB and other Windows apps.  Supports DDE
and
  other frills.  Exhaustive help, online manuals.  Very expensive.

If you have "casual" users of the emulator (i.e., only occasionally
running it) Reflection has server versions which are budget tolerable
for some environments where you need wide deployment without a great
demand for concurrent access.  Available for DOS, Win3.x, Win95/NT, and
Mac, and scripts fairly portable.

Networking is a real issue... if you want NS/VT access you must pay
extra for Reflection.  They have a small DLL file that interfaces the
emulator to WINSOCK.DLL that they charge an arm and a leg for,
relatively speaking.  You might pay "x" dollars for their comprehensive
TCP stack with NS/VT, but still pay "x/3" or thereabouts for that one
little DLL if you want NS/VT (this is the NS/Open product, if I remember
names right).

The other emulators come with integrated NS/VT (Unison, Minisoft).

If you have Win95 and using Microsoft's TCP/IP stack, all of them will
run telnet right out of the box with no add-ons.

A new alternative for those of you with a Un*x box sitting around - the
recent freevt3k project product.  If you have an HP terminal emulator
already and use a Un*x box (esp. 9000) this does the same as telnet but
uses NS/VT protocol, not telnet.  If you don't have HP emulator but have
VT-xxx instead, it will translate "basic" terminal control sequences
(but not to the extent of running VPLUS, unless Randy Medd pulled a
rabbit out of his hat while I wasn't looking, and I'd be pleased to be
corrected!).
If you have an Xterm emulator or terminal, you can use the X-based
hpterm emulator (packaged with freevt3k) to launch freevt3k from and
voila! - you have a free terminal emulator.

There is no un*x-based (other than HP-UX hpterm) freeware/shareware HP
terminal emulator that I'm aware of.  There are a couple of commercial
emulators (I think 'IX/92' or something like that - the vendor is on the
list and may clarify) available for general un*x platforms which can do
hpterm emulation on a vt-xxx terminal (emulator) and at least one of
them does NS/VT as well.

For freevt3k info check http://raven.utc.edu/archives under freevt3k to
find the ftp site for the package.  Dan Hollis used to keep this up but
he has left the list (hopefully the package is still there <?>).  This
was a most noteworthy project that hasn't received much publicity (or
recent activity) but it is a viable, freeware alternative for
noncritical applications.  Kudos to Dan Hollis, Bruce Toback, Randy
Medd, and others for their contributions here (there was one other major
contributor who did the X-based hpterm integration but I don't recall
his name, and can't conveniently look it up right now; my apologies).

Jeff Kell <[log in to unmask]>