If you go to the official Trimble website today, you will struggle to find version 3.5. Trimble, like all software companies, pushes users toward their current products. They generally host the latest versions of their tools (such as the Convert to RINEX tool included within the Trimble Business Center installation or the Trimble Data Transfer utility).
No login? Try the direct legacy path: https://geospatial.trimble.com/support/legacy-downloads → GNSS → Utilities.
The 3.5 release focused on expanding the scope of modern GNSS (Global Navigation Satellite System) capabilities:
