COMSOL Multiphysics has never been free software. Even older versions like 3.5a were sold under paid commercial licenses. The only exception is that some educational institutions purchased site licenses that allowed students to install old versions—but those versions were not "free" to the general public.
Despite being over a decade old, the demand for this specific version persists for a few key reasons: Comsol Multiphysics 3.5a Free Download
: Originally designed for Windows (including Itanium 2 64-bit), Linux distributions, and Solaris. System Requirements COMSOL Multiphysics has never been free software
that was essential for many early automated simulation scripts. ResearchGate Key Technical Specs (Legacy) Supported Platforms Comsol Multiphysics 3.5a Free Download
