Re: Consideration for Rust contributions in Emacs

[Richard Stallman <rms@gnu.org>]

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
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Having parts of Emacs written in some other language would require
future Emacs maintainers to know one more language.  No matter what
that language that might be, its use in Emacs would be a big added
burden.  This reason is very important, and is by itself enough resaon
to say no to whatever other language might be suggested.

There are specific reasons not to use Rust in particular.  Rust
changes too fast; using it in a very large program for which we try to
keep old versions maintainable would be unwise.  Cargo uses a library
archive which includes nonfree libraries, so we should not publicly
refer to its existence.  GCC is a GNU package and we do not want to
replace a GNU package with anything else.  LLVM is not copylefted;
using a noncopylefted package in place of a copylefted package would
be a setback for our cause.  Any of these reasons is sufficient not to
incorporate Rust code.

Rust has a legal problem as well: the trademark licenses of Rust is
unclear, and I can't determine whether Rust is free software.  It is
potentially harmful for anyone to use Rust at all as long as that
remains the case.

The Rust developers could cure that one problem by explaining
concretely what that license requires, specifically for how to
remove the Rust and Cargo trademarks from the compiler.
I asked them over a year ago, but they never responded.

-- 
Dr Richard Stallman (https://stallman.org)
Chief GNUisance of the GNU Project (https://gnu.org)
Founder, Free Software Foundation (https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)