Ever want to run multiple copies of a program at the same time? Yeah, me neither. But when I ran across this tip, I thought, hey, that’d be pretty cool. I could run two copies of Calculator on the same Mac. At the same time! Or even something like NetNewsWire, running one instance of the app that uses one Google account, and a second instance of the app that uses a different account. Pretty neat, right? But how? It sounds complicated. The word “instance” sounds complicated.
Turns out, it’s really fairly simple. Let’s try it out.
Launch the AppleScript Editor, first of all. I know! AppleScript can be scary. But trust me, this is cool. You’ll find this in the Utilities folder, which is nestled in your Applications folder. Once it’s launched, you’ll see an Untitled editing window. Copy and paste the following into the empty window:
do shell script "open -n "
Next, make the Finder active by clicking on the little happy face icon on the left of your Dock. Open the Applications folder, and choose an app you want to run two (or more!) instances of. I chose NetNewsWire. Click and drag that app over to the empty AppleScript editor window, and drop it just to the left of that final quotation mark in the line above, giving you:
do shell script "open -n /Applications/NetNewsWire.app"
Now, click on the Scripts menu at the top of your screen, and choose Compile. Or just hit Command-K on your keyboard. Then choose Save from the File menu, and be sure to change the file type to “Application.” Save it on the Desktop for now.
Once you’ve saved the new app, you can double click on it over and over to launch multiple instances of the app you just chose. Some apps won’t work, like iTunes, but many will. Give it a try and let us know how it goes in the comments below.
Source: Addictive Tips