FYI going from the three number 27.0.91 to the two number 27.1 signifies switching from a development version to a release.
Not really sure what the value of posting this commit to HN is? Firstly many people won't understand the relevance and secondly it doesn't convey much information to those who do, unlike say the typical mailing list announcement or the etc/NEWS file in the repo.
Emacs 27 includes a native JSON parser (as opposed to one written in elisp, used previously). This matters a lot if you're using `lsp-mode`, since the LSP protocol uses a JSON encoding. I've been using local builds of emacs 27 for quite some time, for this very reason.
"Though still a work in progress, our implementation is able to bootstrap a functional Emacs and compile all lexically scoped Elisp files, including the whole GNU Emacs Lisp Package Archive (ELPA). Native-compiled Elisp shows an increase of performance ranging from 2.3x up to 42x with respect to the equivalent byte-code, measured over a set of small benchmarks. "
Not really sure what the value of posting this commit to HN is? Firstly many people won't understand the relevance and secondly it doesn't convey much information to those who do, unlike say the typical mailing list announcement or the etc/NEWS file in the repo.