Do I need an Apple Developer account? [closed]

With Xcode 7 you are no longer required to have a developer account in order to test your apps on your Mac and/or iOS device:

Check it out here.

Please notice that this is the officially supported by Apple, but you'll have to use Xcode 7 or later and your iCloud account.

Before going on - You CAN develop iOS apps and deploy to device from Xcode without developer account, but as far as I know it can be done only on jailbroken devices.

Check this link for more info.

UPDATE

sorry, I thought you meant developing for mobile. check this video about Creation of .dmg files for more information.

ORIGINAL ANSWER

Have a look at the apple developers page to see the different account types. Specifically, the free account:

If you're not ready to join one of our developer programs, you can register as an Apple Developer for free. As a registered Apple Developer you gain access to development tools, resources and information to assist you in creating apps for iOS and OS X. Learn more With the free account you could run your app on any mac OS as well as on an iPhone connected to the mac OS.

With the paid account you could install the app on any provisioning device and submit the app to the store.

If you are developing for the mac and you are not going to publish on mac app store, you do not need a developer account.

You do need an account for any of the following:

• Install an app on an iOS device (even your own one for debugging)
• Publish an app on any of the app stores (either iOS or Mac)

Edit: note that if you do not have an account, your Os X applications will be unsigned. They'll work, but each of your users will get a warning and will need to lower the security settings of his Mac in order to be able to run the application (or, at least, he'll have to approve each application specifically).