The idea is to allow developers who don't want to break backwards
compatibility to use newer functionality that wasn't provided in older
versions of Emacs. This version tries to implement as much as possible
from Emacs 24.2 onwards.

By its very nature it is an intrusive package, as it defines functions,
macros and advice outside of the "namespace", but I don't see any way
around that if transparent compatibility is to be provided (anything
else would just replicate dash, s, f, ...).

As some of the functions are lisp reimplementations of core functions,
there exists the risk of a performance overhead. To minimize this, the
compatibility layer is only applied necessary: Ideally someone using
Emacs 28.1 should have a quasi-empty file, with all the definitions
byte-compiled away.

Eventually I would like to propose adding something like this to
ELPA. It would only makes sense, as more than a few functions were
copied verbatim or quasi-verbatim from Emacs itself.

There still is work to be done, before anything could be added to ELPA,
especially providing tests to ensure that the compatibility layer is
implemented correctly, and making sure that no functions are used that
break the compatibility promise.

So before I continue working on this, I would like to ask if there is
any interest/there are any objections to providing such a library?

-- 
	Philip Kaludercic