Installing SQL Developer 4 on OSX is pretty straightforward. The only issue I had was that it wasn't picking up on updated version of Java and was giving me a error upon launch.
That was a pretty easy fix - you just need to update the SqlDeveloper.conf file with the path. On a OSX (10.8.5) - the path will be something like:
To add drivers for MS SQL Server, download and install the add in: jtds-1.3.1.jar (not 1.2) following these instructions for Third-Party Drivers:
Get 1.3 here: http://sourceforge.net/projects/jtds/files/jtds/1.3.1/
Download and extract to a permanent folder follow instructions on adding into the Application above.
Here's the part that seems to elude most users - especially if you are connecting using Windows Authentication. The GUI panel just doesn't seem to work.
On a OSX - you will also need to modify the "connections.xml" file by adding the DOMAIN value such as:
This folder is hidden and is located at:
Note: To access hidden files, navigate to /Users/<username> and the click the "Go" top menu drop-down and select "Go to folder..." Type ".sqldeveloper" (without quotes) and then follow the path from there. Directories that start with "." are hidden by default.
Once the above is saved, just try connecting from the main Connections Tree by right-click the connection and choose "Connect"
Note: To see what Java version you are running in OSX you can issue this at the cmd line:
java version "1.7.0_51"
Java(TM) SE Runtime Environment (build 1.7.0_51-b13)
Java HotSpot(TM) 64-Bit Server VM (build 24.51-b03, mixed mode)