在 OSX 環境中，預設 Eclipse 只能開啟一個，當我們需要同時間開啟兩個 workspace 時，就需要以指令的方式去開啟另外一個 Eclipse instance：
這邊以STS ( SpringSource )
切換到 STS 安裝路徑
open -n STS.app
It's pretty simple.
At the command line, navigate to your Eclipse installation. For example:
or wherever you installed Eclipse to.
Once there, launch Eclipse as follows:
This will launch eclipse and immediately background the process.
Rinse and repeat to open as many unique instances of Eclipse as you want. I'm not sure if there is a way to do this from the GUI, but I'm comfortable at the command line so it's a no-brainer for me.
Hope that helps!