OS x Tutorial How to install an app from an unidentified developer

The main reason why some software cannot be installed because of the hint "from an unidentified developer" has been frequently asked recently because Apple enabled new security mechanisms in the Mac OS X 10.8 Mountain Lion System, only for Mac apps The store downloads the software and the application that has the developer ID signature, the default trust. From then on the mountain lion system can only install software that is downloaded by the channel, or software developed by a recognized person, i.e. software that must be audited by Apple. This is, of course, for user security considerations, but for independent developers, unsigned security is also affected, the installation will pop up the warning box as shown below: "Can't open xxx, because it comes from an unidentified developer." As shown in the figure below

See many people on the internet after the Apple upgrade Mountain Lion system because "from the unknown developer" can not install some software problems, in fact, the system preferences in a few clicks on the line. Details are as follows

Update: More reader comment feedback: control and then open the line.

Click the Apple logo in the upper-left corner of your Mac screen and select "System Preferences ..." in the drop-down menu. In the Settings panel that pops up, click on the "Security and privacy" icon for the small house on the first line.

Select the "Generic" tab in the Security and Privacy settings panel (it should be there by default). See the above screenshot of the small series with a red box to mark a few of the options, the download of the application from the default "Mac app Store and recognized developers" to "any source" on the line.

But the button is grey and cannot be selected ... Locked, click the Lock button in the lower left corner to unlock it.

The system will ask you to lose your password.

The settings can now be changed, and the software that is not installed by the Mountain Lion system warning can be installed properly.