Photopea is a free, web-based photo editor that runs entirely in your browser.
The software does not modify the host computer's registry, meaning it leaves no trace behind when closed.
Since these are modified versions of the original code, they are prone to instability.
The "Portable" version, however, represents a community-driven phenomenon rather than an official Adobe release. The Rise of the Portable "Ghost" (Early 2000s - 2010s)