ControlMyNikon is tethering software to control various Nikon cameras.

First of all, many older cameras are not supported.
Eg. a D70 isn't supported, neither is a D50 or D2 series, nor D100. But a D200, D80, D40, D40x and D60 are supported, so check whether yours is.

ControlMyNikon (CMN) is, in a word ... brilliant!

I remember trying out the trial version of Nikon Camera Control Pro(CCP) about a year back and while it worked well, it didn't seem as 'full featured' as it could have been.

In particular I don't remember CCP allowing the user to adjust focus 'manually' whilst in Live View mode(that is via the PC, in small increments).
As I remember CCP, you either got focus or not.
The handiest feature in CMN that it has this feature when using Lv mode where you can adjust the focus point in small step increments using what the author call the 'focus pad', and allows the user to adjust the focus point as required. The amount of adjustment is variable, say from an Attometer to a Kilometer if you prefer, in a single 'step'.
A step is a single focus adjustment in one movement.

LiveView looks quite good on the PC screen, and I dare say a screen with a higher pixel density may look even nicer, but don't expect to see your 900x600 pixel images any clearer on a UXGA screen as you zoom in. You simply zoom in and see basically what you would otherwise see on the review screen on the camera.
The review screen on the camera remains inactive, so you save battery power on the camera.
Another handy feature I noticed(in Lv mode) was this sensor health meter, which basically indicates how 'hot' or 'bothered' the sensor is at any point in time(in real time), and gives you an estimated remaining time readout at the bottom edge of the LiveView screen on the PC.

So, why is this software handy?

Because:

A. the price is good! US$10, which works out to about AU$9.50.
You can't buy nothing for under $10 nowadays, so this price seems almost too good not advantage of.. even if I(or you) only use it a few times.

B. Focus stackers!! This is one of the easiest (maybe cheapest) methods to get your focus stacked images without too much toil, trouble or turmoil.
This software has scripting, but already has a handy Focus Stacking ability built in. So set up your subject, work out how much focus distance you need per step, work out how many steps you need and press the shoot button. It has automatic exposure delay as well as an added delay mode specifically for focus stacking too.
The software has built in integration with a focus stacking software called CombineZP which is a free focus stacking program.

Another handy part of the LiveView mode is realtime DOF preview, which doesn't happen on the camera in Lv mode(unless you have a non CPU lens).
So, you get to see realtime DOF preview through a nice bright PC screen, not some dingy dark viewfinder.. and if you stop down far enough, you even get to see your camera's current dustbunnies in real time too!

Personally I have very little to zero need for tethering software, but for $10 for such a feature rich software, why not!
I'm sure I'll find a way to use it for the majority of my uses.

There are a few minor bugs here and there, but they don't seem to be major.

As of current, my only gripe is that there is no option to save images to both the PC hard drive AND the camera's card(s), but there is a mirror feature in the program to save captured images to two different locations.
And that my old D70 isn't supported or any D2 camera isn't.

File naming seems to be quite flexible, but I have yet to work out how to maintain the camera's file names, even tho I always add a prefix and or suffix to the name .. I simply want to keep a track of the camera's exposures in an easy to find manner.

anyhow .. I'm not usually rating stuff I write a review on, and even tho this isn't really a review, and more of a 'user experience' wher eth euser is of limited experience(with both tethering software and focus stacking!!), I'm rating this software 10/10(even tho it has some minor usually inconsequential bugs).
Crikey! ... for $10(which is as good as 'for free') you really can't go wrong.
There is a 14 day trial if you're interested but unsure.

Anyhow. That's it!
you'll probably start seeing some focus stacked images from me soon, as up to getting this software, there was no way in hell that I'd bother doing focus stacking without some sort of automating process, and this program looks to be just the ticket