This is a discussion on Mountain Lion 101 within the Mac OS X forums, part of the Mac Software category; Gatekeeper isn't the most obvious feature of the new OS X Mountain Lion system that you probably downloaded and installed yesterday, but it might be ...
Gatekeeper isn't the most obvious feature of the new OS X Mountain Lion system that you probably downloaded and installed yesterday, but it might be one of the most important. Gatekeeper essentially oversees a list of verified developers who have applied for and received a Developer ID from Apple.
It also allows you to specify whether your Mac will install apps only from the App Store, from the App Store and this list, or from anywhere you want. If you choose the Mac App Store only, you'll be able to make sure that everything you install has gone through Apple's approval process, which is about as protected from malware as you can get.
When you installed Mountain Lion, every app that was already on your Mac got a free pass as far as Gatekeeper is concerned. The apps were grandfathered in as already having been run and cleared; since Gatekeeper works by preventing the first launch of an app, those apps are OK. In fact, you can keep the "Mac App Store and identified developers" setting turned on for safety while still installing and running non-signed apps; just right-click (or control-click) the unsigned app and choose Open. Gatekeeper will prompt you for a single-app exemption and if you're OK with it, the app will launch from then on.
Now, not everybody appreciates Apple's "walled garden." Some developers take issue with the fact that they need to be "verified" by Apple before releasing and running software on the Mac. Gatekeeper is also responsible for "sandboxing" applications, which means keeping applications from changing files on parts of your computer that they don't usually interact with (though this does cause problems for apps that do want to dip into your personal system files, usually just to make things easier on you).
At any rate, sandboxing and Gatekeeper are a reality for now. If you want to tweak your Gatekeeper settings, you can find them in the System Preferences screen under Security and Privacy.
Dismiss Desktop Notifications in OS X Mountain Lion Immediately with a Swipe
Want to quickly dismiss a desktop notification without opening Notification Center in OS X? It’s easy, just hover over the notification with the cursor and use a two-fingered swipe gesture from left to right, swiping the alert to where Notification Center appears, and the alert will quickly zip away in a blur.
This gesture doesn’t close the notification, it just moves it off of the desktop and stops it from hovering over everything else. You will still be able to find it with all other alerts by opening NotificationCenter on the Mac. Remember, if you get tired of the desktop notifications you can always temporarily disable the service by option-clicking the menu bar icon Option+Click so it turns from black to grey.
For those who have an iPhone, iPad, or iPod touch, you’ll find this to be very similar to the way dismissing notifications in iOS works by swiping onscreen too.
9 Tricks for the Full Screen Slideshow Feature in OS X
Did you know the Finder in Mac OS X has a built-in instant image slide-show feature? It’s part of Quick Look, and though it’s been around a while, it’s a little known feature that is really great when you want to quickly show off a group of pictures, or even if you just want to take a single picture into full-screen mode without having to launch an app like Preview.
Select a picture or group of images from the desktop, then use the following:
Option+Spacebar to launch image(s) into the full-screen slideshow mode
Spacebar to pause/play the image slideshow
Left Arrow to go back, Right Arrow to go forward
Gesture with two-fingers left to go forward, two-finger gesture right to go back
Option to view smaller images at actual size
Click “Index Sheet” to view thumbnails of all images in the slideshow
Click “Add to iPhoto” to import the image into iPhoto
Hold Control key and use a two-fingered back or forward swipe in to zoom into the photo
Escape to exit
The zoom features are somewhat independent of the slideshow and must be enabled in order to work, this is very easy in OS X Mountain Lion since it can be activated with a keyboard shortcut.
Previous versions of OS X could enter a more limited slideshow through Quick Look by hitting Command+Option+Y, so if you’re still on Snow Leopard try that instead. It doesn’t have all the features that were added to Lion and Mountain Lion, but it’s still pretty good.
Start Web Sharing in OS X Mountain Lion the Easy Way with a Preference Panel
Many people have noticed the simple web sharing option was pulled from System Preferences in OS X Mountain Lion. The server software still exists and you can start Apache server on your Mac yourself within a minute or two of mucking about in the Terminal, but for some people the command line is just too much of a hassle. If you’d rather have an easier approach to starting the hidden web server in Mac OS X, grab a free third party preference with the most obvious name ever, WebSharing.
Double-click to install the preference pane, and then starting Apache becomes just a matter of flipping a big ON and OFF switch, acting as a front-end to apachectl in the command line. Once it’s running everything else is the same, the directory being served is still your user ~/Sites/ folder so toss in an index.html file and have at it.
43 Amazingly Gorgeous Secret Wallpapers Hidden in OS X Mountain Lion
Did you know OS X Mountain Lion includes 44 ridiculously beautiful high resolution wallpapers? They’re hidden inside the four equally attractive new screen savers and feature some truly stunning scenery from National Geographic, the Hubble Space telescope, and some amazing photographers.
Each image is a whopping 3200×2000 resolution, here’s how to access these on your Mac:
From the OS X Finder, hit Command+Shift+G to summon Go To Folder and enter the following path exactly:
Copy the four well-labeled directories “1-National Geographic”, “2-Aerial”, “3-Cosmos”, “4-Nature Patterns” to the Desktop or elsewhere for easy access to the high res images
A few thumbnail previews are shown below, but you really need to check them out yourself in full resolution, they’re stunning.
National Geographic:
Cosmos
Aerial
Nature Patterns
You will find a handful that are also in the default OS X Mountain Lion wallpaper collection, but the vast majority are totally new.
Banish Those Mountain Lion Banner Notifications With A Swipe [OS X Tips]
OK, so maybe I’m too impatient, but waiting for those otherwise-useful banner notifications in OS X Mountain Lion is rather annoying. I’ve long grown used to the Growl-style pop up badge, which has an actual close button on it. The new banner notifications in OS X 10.8 have no such thing, and when I want to click on something underneath them, my ire is quickly aroused. Where’s the Close button!? iMessages gets one, why not general notifications and alerts?
Well, there isn’t one, and that’s just the way it is. Luckily, there is also a way to close these 5-second tests of my patience, though.
When the notification banner pops up, hover your mouse over it. If you’re using a trackpad like me, you just need to swipe to the right with a two finger gesture, much the same as when you’re swiping through a cover-flow-style bunch of images in the Finder, or moving forward and back while using Google Chrome or Safari. Very simple, very easy.
If you’re using a Magic Mouse, it’s even easier. Exactly one finger easier, in fact. Use a one finger swipe to the right, after hovering over the notification window when it pops up. The pesky little thing will go away and you can resume your zen-like exterior of calm.
This will come in really handy when I head up to my Mac Mini and see that all the iMessages I’ve been trading back and forth over the last several days are there in one huge long list. Waiting 5 seconds for each one to disappear is a bit much.
Open a File with Any App Directly from Quick Look in Mac OS X
Quick Look is one of the most handy features in Mac OS X to quickly get a preview of files, but you can also use it as an application launcher of sorts to quickly send a file to a compatible app. Similar to the “Open With” menu that can be summoned by right-clicking on a file within the Finder, but Quick Look gets the upper hand because it provides a preview of the file in question. Here’s how to use this feature:
Select any file in the Finder and hit Spacebar to see it in Quick Look
Right-click on the “Open with …” button to reveal all other app choices
This works with just about any file type, so long as the file type is recognized and there are applications installed that could read it. If you see apps in the list that shouldn’t be there given the file type, clearing the Open With menu will impact both Quick Look and the right-click option.
As usual quick Quicklook, you can also enter the slideshow from here if it’s a group of images that has been selected.
There are a variety of different ways to transfer or share files between Macs, and we’ll cover the three easiest methods that are applicable for just about movement of files. AirDrop is unique to newer versions of OS X but is by far the simplest, iMessages lets you send files to another Mac over the internet, and the third approach using AFP works with every version of Mac OS X ever shipped, so even if you’re trying to copy a file from an old Mac running Tiger to a newer one with Mountain Lion, you’ll be able to get it done.
Transfer Files with AirDrop
By far the easiest method is to use AirDrop, and so long as both Macs are running OS X Lion or later you can use the feature. The best part? You don’t even need to be connected to the same Wi-Fi network, as long as your computers are within range of one another an ad-hoc network will be created between the two Macs to send the file. AirDrop is the fastest way to send files between Macs hands down and there’s virtually no configuration required to use it.
From the OS X Finder:
Hit Command+Shift+R to open AirDrop
Wait for the other Mac to appear, then drag and drop the file(s) to the Mac to transfer files to
On the receiving Mac, accept the file transfer
AirDrop is extremely easy to use, and remember if you have an older Mac that doesn’t officially support AirDrop, or if that Mac doesn’t have Wi-Fi, you can enable AirDrop support on old Macs and through wired ethernet connections with a simple command.
Send Files Locally or Over the Internet with iMessage
Want to send a file to your friends Mac in another state? Messages for OS X is the easiest way to go. From Mountain Lion’s Messages app onward, all you need to do is:
Open a new Message to the recipient
Drag and drop the file into the iMessage window and hit return to send
When finished transferring, the recipient can just double-click the file to open it or right-click to save it
iMessages makes transferring files between remote Macs extremely easy, and Messages will accept just about any file type, whether it’s images, documents, movies, zips, you name it. An added bonus? iMessage also lets you send the same files to iOS devices like iPhones, iPods, and iPads, so long as iMessage is set up properly in iOS 5 or later.
Traditional AFP File Sharing
AFP (Appletalk Filing Protocol) is the old-fashioned traditional route to share files between Macs, and though it takes a moment or two to setup it has some major advantages like being able to map network drives for constant access and to transfer files between Macs and Windows PC’s as well as across Macs running any version of OS X, whether it’s 10.1 or 10.8.1.
File Sharing needs to be enabled on all Macs that you want to use the feature on, here’s how:
Open System Preferences from the Apple menu, and click on “Sharing” panel
Check to enable “File Sharing” on all Macs you want to share files between
From the OS X Finder, hit Command+Shift+K and then click “Browse” to find and connect to the desired Mac
Enter login credentials to connect, and now you can use the other Mac like any other folder in OS X, drag and drop files to copy
If you’re going to move very large files between Macs the traditional File Sharing approach is probably the best method of transfer. It’s highly reliable, and has the greatest range of compatibility between all Macs and versions of OS X.
Remote Login with SFTP & SSH is another great option for secured transfers to and from your own Macs when you’re away from home, you can read more about enabling the SSH server here.