I noticed, and enjoyed, that variation too. A few of my software products have gone through multiple frameworks and rewrites, but from the user's point of view

I noticed, and enjoyed, that variation too. A few of my software products have gone through multiple frameworks and rewrites, but from the user's point of view they appear to have remained one evolving entity. My phone/personal-digital-assistant also has kept its name for 21 years, but has gone through a series of reincarnations.