COBOL: Most of the legacy softwares written in COBOL in bigger industries have been migrating to newer technologies. Also, the interest over the time is decreasing tremendously.

trends.google.com/trends/explore

What I think will die out:

• Cobol,
• Object-Pascal and Pascal
• ABAP (SAP is switching to JS in their newer frameworks, see UI5)
• Objective-C (Apple was the biggest user, and they switched to Swift)

What I hope will die out:

• C++ (in favor of Rust)
• Java (in favor of Kotlin and Go)
• CoffeeScript (in favor of virtually anything)

Update: It seems Kotlin is starting its journey to do just that

I think programming languages can never go obsolete. They can, however, go unused over the time because of other attractive alternatives.

That being said, most of the unheard programming languages will remain completely unused in the upcoming years. For example:

1. CAJOLE
2. LISP
3. PROLOG
4. Rebol
5. LOGO

Cheers! 🍺