How Do I: A Macintosh OSX Q&A

User Questions

Q: Run Multiple Instances of an Application

There are a number of workaround for this problem with OSX. Apple designed OS X to behave like the System 7, Mac OS 7.6 days whereas a program uses a single unified system interface and only one will launch at a time. The interesting thing is that this is not a kernel level restriction since OSX is built on FreeBSD and therefore the underlying system supports launching multiple instances of a program.

Answer #1 - Use the command line. Running a program with the "-n" flag tells the system to open a new instance of the same program application.

open -n -a "APPLICATION NAME"

example:

open -n -a /Applications/Safari.app/

Answer #2 - Create a copy of the program with a different name and run each individually. This is less desirable because you end up with disk space wasted in having several copies of the same software on the disk.

Answer #3 - create a 2nd user account on your Mac. You can have the app open in both accounts, signed in to different accounts. If you enable fast switching, you can very quickly switch between the two."

Some software will not behave correctly when running multiple instances of it at the same time. This has to do with how the software may cache data, or save configuration files. In some cases one of the three methods above might work better than another. Each method has limitations. The best method is Answer #1 for most general applications.