Macintosh users have been waiting for a year to get their hands on Apple's newest big cat - the operating system called Mountain Lion, or the more boring Mac OS 10.8.
Apple has been on a 12-month cycle for major revisions to its computer operating system for a few years now, and this year's version has more than 200 new features.
Apple says more than 3 million copies were downloaded in the first four days.
The upgrade is available in the Mac App store online.
So what's new? I can't possibly cover it all, but let's dive in to the highest-profile features.
MESSAGES: Apple has quietly been waging a war against telephone companies and their high-dollar text messaging for more than a year now with its own messaging system for iOS devices called iMessage. iOS users can send each other text messages for free using Apple's servers.
Now, with Mountain Lion, Apple brings iMessages to the Mac OS with a program called Messages.
Because it uses an email address instead of a phone number, you can message between an iPhone or iPad and a Mac.
Start a conversation with someone on your iPhone and continue it on the Mac when you get home.
You receive iMessages on both your phone and computer.
It works well, but there's one missing piece of the puzzle I'm waiting for - the ability to sync a phone number and email address to receive all text messages on the computer.
Right now, traditional text messages sent to my iPhone's number don't show up on my computer. I wish they did.
NOTIFICATION CENTER: Another feature from iOS makes it over to Mac OS.
iPhone users have had the Notification Center since iOS 5 last year.
Exposed by swiping with two fingers on a track pad, the Notification Center is the one-stop shop for mail, calendar, iMessages or any other app that wants to notify you of something.
It's a nice addition. You can select how each app notifies you, either with a banner that appears for a few seconds and then disappears or with an alert on your desktop that stays put until you click on it.
DICTATION: Apple has toyed with voice control over some Mac OS features in previous years, but this is the first time the company has included voice dictation for any instance where you can type.
Once it's enabled, you press the keyboard's function key twice and speak what you want to type.
You can pronounce the punctuation and line returns to dictate entire paragraphs.
The more you dictate, the smarter the dictation becomes as it learns from your voice characteristics.
AIRPLAY MIRRORING: AirPlay is a neat feature that's underused, from my perspective.
It's the ability to play music or videos from your Mac, iPhone or iPad to an Apple TV and onto your big-screen TV.
Mountain Lion takes AirPlay one step further with the ability to stream your entire computer screen to your TV wirelessly.
You just need a computer with Mountain Lion and a second- or third-generation Apple TV.
It works well with apps like HBOGo or Hulu Plus that previously didn't allow AirPlay in their players.
You do need a Mac from 2011 or later to mirror over AirPlay.
POWER NAP: When you put your Mac to sleep, not much happens. With Mountain Lion, your Mac doesn't sleep - it Power Naps.
This means the Mac is doing things in the background while it's sleeping.
What kinds of things?
Oh, checking for new mail, calendar invites, Notes and documents that sync from iCloud, downloading software updates and backing up with Time Machine, all without any system sounds, lights or fans.
Of course, you'll need one of the very newest Macs with built-in flash storage to use this feature - meaning at least the Macbook Air 2011 or a retina display Macbook Pro.
These are just a few of the 200 new features. At about $20, this upgrade is a no-brainer if your Mac is running Leopard or Snow Leopard.
Almost all Macs from 2008 or newer can run Mountain Lion.
I think everyone can find a feature or two or 10 that make their lives easier.
I've been using it since the release day, and I keep finding new things I like.
-Pros: Tons of new features. Cheap. AirPlay Mirroring.
-Cons: Too many features leave older Macs behind.
-Bottom Line: Mac users have spoken: Mountain Lion is a winner.
-On the Web: apple.com
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