I've noticed a strong parallel between Microsoft's .NET Framework 4.x and Oracle's JDK 8.x series. Even though newer versions keep rolling out — .NET Core, .NET 6/7/8, JDK 11/17/21 — these older versions just won’t die.

A few reasons:

- Heavy enterprise usage, especially in midcaps and MSMEs.

- Industry inertia — teams hesitate to rewrite working systems without a compelling business reason.

- In some cases, older stacks are more stable and “battle-tested”, especially for use cases like WinForms or thick-client apps.

It's kind of ironic that even today, the default .NET version baked into fresh Windows installs is 4.6 (or nearby), not the shiny new .NET 8/9. Meanwhile, Oracle still offers JDK 8 — albeit behind a paid support wall — much like Microsoft continues to patch .NET 4.x via Windows Update.

Eventually, these older branches will be sunset. But given their stability and widespread industrial use, I feel like that day might be decades away rather than years.

Curious to hear — how do you see this transition unfolding? And are there any good examples where teams actually migrated away from 4.x or 8.x successfully?