. Because they are not official, they do not receive critical security updates. System Instability:
In some jurisdictions, software older than 10 years that is no longer sold by the publisher is considered "abandonware." Reputable archives (like VETUSWARE or Archive.org) sometimes host the original CS5 installer. You would still need a serial number (legally, you must own one).
: Advanced High Dynamic Range tools for merging multiple exposures. Mixer Brush
If you're looking for a reliable and feature-rich portable version of Adobe Photoshop CS5, I highly recommend giving this software a try. Just ensure you have a decent computer and compatible plugins to get the most out of this amazing tool.