Opening Applications

So for the last month I have been

super busy, working and had a need to open two instances of my Java IDE of choice Eclipse, but like some applications, there is no clear way to have two separate instances running at once.

To open a second instance of any applications on your Mac all you need to do is open the terminal navigate to the root applications folder

cd /Applications

And issue the open command

open -n /<applicationName>

The man page for the command says that it does this

Open a file in its default application

The -n is used to open the file in a new instance of its application.

A word of warning forcing applications that are not designed to have multiple instances running, to have multiple instances running could result in odd side effects, for instance in eclipse each instance has to access a seperate workspace.

I don’t post this because it’s some ground shattering stuff, it is however a good place to start looking at the terminal and realising that it is not that scary.


Thank you, thank you, thank you for this tip! I have been wanting to run multiple instances of Bluebeam Revu (pdf editor for engineering) on my MacBook for quite a while. I knew about the open command, but it just did not occur to me to read the man page and find out all the switches. This will be very helpful for me.

You can also use the -a option to tell it that you’re looking to open an application. So, if you wanted to open a new instance of, for example, you could do this:

open -n -a vlc

There are two advantages to using -a:

  1. You don’t need to navigate to the Applications folder first. It works from anywhere.
  2. You don’t need to call the application You can just call it vlc.

By the way, you can also combine the -n and -a options together like this:

open -na vlc