Historical Context
Win4Lin 4.0
Win4Lin 4.0 represented the more mature workstation phase of the product family, with broader application coverage and a clearer commercial pitch for Linux desktop holdouts.
What changed in the 4.0 era
The product line broadened beyond novelty and sold itself as a practical bridge for users who wanted Linux as the host OS without losing access to business applications tied to older Windows versions.
Why it matters now
Modern compatibility work still centers on the same question: keep the workflow, lose the reboot. The implementation layer changed, but the user need did not.