This free software is an intellectual property of Rohde & Schwarz GmbH & Co. KG. Rohde & Schwarz RSADSIF belongs to Development Tools. The most popular version of the program is 2.0. Also the tool is known as "Rohde Schwarz RSADSIF".
From the developer:
This Application Note presents means to integrate R&S Test and Measurement instruments into the Agilent® ADS® Design System. Methods to include R&S Instruments are presented, accompanied by a free-of-charge software solution which is provided with this application note. It makes it very easy to include R&S Instruments into your ADS environment and your design flow.
You may want to check out more software, such as Rohde Schwarz RSIB-VISA or Rohde & Schwarz dBCalculator, which might be similar to Rohde & Schwarz RSADSIF.