Tweaking Your New Mechanical Keyboard
If you’re like me, a dude in his late thirties who still remembers his first computer (Apple IIe, technically my dad’s computer) and that cool click-clack-ity sound it made, you might appreciate that what’s old is new again.
Suffice it to say, like a lot developers in the last few years, I’ve become interested in the tactile satisfaction and usability of mechanical keyboards.

An old Apple IIe which came with a really noisy, awesome mechanical keyboard (the only keyboard option for the first few decades of home computing).
Anyway, I can’t exactly remember exactly how I first came upon the idea of getting a mechanical keyboard — I think it was this guy’s post on quora where he had included a picture of an awesome, custom built, mechanical keyboard, which looked something like this:

In any event, rather than waiting for the Massdrop order to fill up, I searched around for a solid, cool-looking mechanical keyboard that was also Apple-compatible without too much tinkering. It didn’t take much Googling before I happened upon this baby:

At right around $80 USD, the Nixeus Moda Pro is as affordable as it is well-built. You can get all the details here, but the first question is of course:
“Will it work on my Mac? And if ‘yes’, how much screwing around will I have to do before I feel at home on it?”
The answer is pretty much “yes” and “not too much”, respectively.
Here’s how it works:
Step 1. Once you get your Moda Pro unsheathed and presented to the world, there’s a little plastic packet with a few Apple keys and a black plastic tool that looks like a ring a villain would wear. It’s pretty intuitive, just slide the prongs under the Windows key and the two alt keys and replace those with the two Apple cms keys and the one Option key they give you. You’re just making your Moda Pro key look like your current Apple keyboard here, although it’s not going to be a perfect match. Here’s how mine looks now:

Ok, so it’s not a total match to an Apple keyboard as you can see, even after you replace the option and cmd keys. The media keys up top basically work the same as the player and volume keys on a standard Apple keyboard, you just have to use the Fn key to the right of the space bar:

The main thing though is that you won’t have an Option key to the right of the right-side Command key, as you would normally with a standard Apple keyboard. Just a little heads up so you won’t be surprised.
Ok, so now on to how you actually configure this thing.
Step 2. Download and install Karabiner, an open source and well-supported keyboard customizer application for OSX.
Step 3. Once you have Karabiner installed (and no conflicting keyboard mappers installed, which Karabiner will alert you to), you actually leave Karabiner alone for a second and go right to Systems Preferences. There you go: Keyboard > Modifier Keys > In the dropdown Select Keyboard menu select “USB Gaming Keyboard” and set up the Cmd and Option keys properly like so (basically swapping Option and Cmd, due to how your Mac will initially see the Moda Pro layout):

That’s actually most of the work. But you’ll notice that the Cmd on the right side still doesn’t work, even though it’s being activated when you press it, according to Keyboard Preferences Show Keyboard Layout viewer it’s still being registered as an Option key. Here’s where Karabiner comes in.
Step 4. Find Karabiner in your Applications folder, open it, and you’ll see this:

Scroll down or search until you find Change Option_R Key (Right Option):

Once you’ve found Change Option_R Key (Right Option), expand it with the arrow icon and check the box that says Option_R to Command_R. This will now register the right-side Cmd key properly as a Cmd key and not an Option key.
So the only catch with this is that you have to let Karabiner run in the background the entire time you user your Mac with this keyboard. It will load an icon in the menu bar and pretty much stay out of the way after that, but just another heads up.
That’s it. Enjoy your new mechanical keyboard!