Download of Visus 5.6 was on the developer's website when we last checked. We cannot confirm if there is a free download of this software available. The actual developer of the program is SP-Software GmBH. According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software.
From the developer:
Visus is the ultimate productivity tool for teams. If they’ve run into the problem of having too much knowledge and not enough time to access it, Visus is the answer to their problem. With just a few simple questions, they can instantly access the valuable information they need and make decisions more quickly. Visus gives they the information they need when they need it. Visus simplifies the process of researching and finding information.