While the phrase "No activation required" sounds like a benefit to the user, it implies significant technical modifications to the software's architecture.
However, it is crucial to clarify that While Adobe has offered mobile apps and cloud-based solutions, the concept of a "portable" desktop app (running a full Gigabyte-sized suite from a single executable) is almost exclusively the domain of third-party modifications.
In essence, users searching for this phrase want a complete, professional photo editor that they can carry in their pocket, use on any Windows PC (often without admin rights), and never have to enter a license key.
In an era of Creative Cloud subscriptions, CS5 holds a specific nostalgic and functional appeal: