GateKeeper will block files from opening that it thinks are command line apps.

I was trying to open in TextWrangler sample .ncx and .opf files that I had downloaded from an Amazon forum. The Mac saw them as command line apps, and when dragging them onto TextWrangler’s icon, I got an alert from GateKeeper. Since they’re files, the contextual menu “Open” command didn’t work. When I went into the Security preference pane to temporarily disable GateKeeper, I noticed that it had a message about the last thing that was prevented from opening, with a button to open anyway, and the file opened right away in TextWrangler. (Note that I didn’t try changing the “open in” app using Get Info, which may have worked also.)

Source: Mac OSX Hints

So, as a paid user of MobileMe, Apple provided you with 20 GB of iCloud storage. Suddenly, in October ’13, Apple removed 15 GB of that, and you’re getting messages from Apple that your iCloud storage is getting full, or even the dreaded message, “Your iCloud storage is full… You can no longer send or receive messages with your iCloud email address…” Apple is strongly encouraging you to buy more storage. Do you have any other options?

As Apple suggests, go to System Preferences > iCloud > Manage > Mail. At that point, Apple recommends, “To free up storage used by Mail, erase messages in the Junk and Trash folders.”

That’s a good start, but that’s not nearly enough. If that shows that Mail really is the culprit in hogging your iCloud storage, try deleting the attachments from your received and sent mail! That can reduce your iCloud storage tremendously. (That alone cut mine down from about 4.8 GB to 1.2 GB).

To find your mail with attachments, in Apple Mail, you ca …

Source: Mac OSX Hints

A new tab can be added to a Finder window that already has tabs by dragging a folder’s proxy icon to the plus sign that appears in the tabbed window.

You probably know you can drag the proxy icon of a Mavericks Finder window to another Finder window’s tab to move or copy it to the tab’s folder. You can add the folder as a tab to a Finder window that already has tabs if you drag its proxy icon to the plus (+) icon next to the right-most tab of the tabbed window.

Source: Mac OSX Hints

In Mac OS X 10.9 Mavericks, the functionality to zoom in and out of PDFs in Quick Look is back: Press and hold the Option key while scrolling with two fingers.

Moreover, the images in Quick Look can be zoomed in to actual size by just pressing the option key.

Unfortunately, it is no longer possible to select text from text files in Quick Look.

Source: Mac OSX Hints

As you probably know the brandnew iOS devices like the iPad Air enable you to download the iWork and iLife apps for free. What I didn’t know is that once you downloaded them to your new device, they will also be available for free on your older devices.

In my case I bought an iPad Air and also got the apps for free on my older iPhone 5. It makes kinda sense, since the download is tied to your Apple ID, but I still didn’t think about that until I noticed them downloading on my iPhone. In my case Automatic Downlods were enabled. So if you have this unchecked you just need to download the apps manually. The will show the Cloud icon instead of a price.

No great hint, but maybe someone else didn’t think about that, too.

Source: Mac OSX Hints

When you’re playing music in the Music app in iOS 7, there’s a thin red playhead that you can drag to adjust the song’s playback position. Tap and drag it around for what Apple calls “Hi-Speed Scrubbing.” (Why it’s not “high,” I can’t say. Maybe the programmers were hi.)

Here’s the hint: You can adjust the speed at which you’re scrubbing through the song, if you need finer-grained control: Tap and hold on the red line, and then drag your finger upwards.

As you drag up the screen, you’ll note that there three other gradations of scrubbing speed: Half-Speed Scrubbing, Quarter-Speed Scrubbing, and finally Fine Scrubbing; that last mode lets you scrub through the song second by second.

Source: Mac OSX Hints

In Mavericks, when you QuickLook files, there’s an Open In button at the upper right, which lets you open the previewed document in the default app associated with the file in question.

But what if you want to open the document in a different app? For example, you’re previewing a Microsoft Word document, but would prefer to open the file in Preview instead.

Just click and hold on the Open In Microsoft Word button, and a list of other, compatible apps appears. Choose the one you’re after, and you’re good to go.

Source: Mac OSX Hints

Mavericks offers a lot less resolution options in the “Scaled” list than 10.8 or earlier did. This can be a particularly severe problem if the resolutions that it thinks your projector supports are not, in fact, supported by it at all, as was the case with my setup.The fix for showing the extended list of possible resolutions in Mavericks is undocumented, so far as I can find, but incredibly easy:

In the Displays preference pane, hold down the option key and click the “Scaled” radio button. This will toggle on and off additional resolutions for the device (including more scaled resolutions for the built-in display in MacBooks).

I’m not aware of any radio button ever having worked that way before, so it’s easy to miss.

If your external display isn’t showing an image at all because the OS got its “native” resolution wrong, you will of course have to click the “Gather Windows” button at the bottom of the preference pane to bring the w …

Source: Mac OSX Hints

If you use AppleScript applets to interact with UI elements, you may quickly find out that in Mavericks all seems to be broken. Every run results in System Preferences being opened to the pane that used to control UI Element Scripting, and finding the new controls in Security & Privacy -> Privacy -> Accessibility seems to have no effect.
This is a result of Mavericks splitting UI control authorization into per-app settings, combined with the Lion feature of remembering what windows an app had open when it was last closed.

Mavericks recognizes the app uniquely only as long as the app doesn’t change.
WindowState information is stored in the app if you have permissions to modify it.
These two features end up caught in a fight.

The following Terminal command will prevent this by passing ownership of the applet to root and blocking you from editing it without authenticating.
sudo chown -R root:wheel AppletName.app …

Source: Mac OSX Hints

Mavericks now considers each monitor a “Space”. As a result, apps launch and have their menu bar in whichever monitor they were launched from. However, it’s easy to assign apps to each monitor. Here’s how:

First, you need to create an additional space in Mission Control. You can add it to either monitor.

Having done that, then when you right-click on an app in the Dock, you will see the option to assign the app to All Desktops, Desktop on Display 1, Desktop on Display 2.

Source: Mac OSX Hints