6to5 (ES6 transpiler) is now renamed Babel
github.com
github.com
Good move because even if it started with ES6, it now supports more (e.g. some ES7 features and JSX) so the name didn't fit anymore.
I find it quite annoying when people name their project without consideration for other people in the open source community.
Other historical examples include Mozilla Firebird, which was renamed to Thunderbird after loud complains of the Firebird database community, or Twitter's Fabric, which clashes with Fabric (http://www.fabfile.org/), another Python project.
Indeed, a quick googling shows there's a Python Babel, an Eclipse Babel, an Emacs Babel, a TeX Babel, a Babel language, and an Open Babel for chemistry. I'm sure the addition of this new JS Babel won't inconvenience anyone too much.
If anything, I think the real issue is open source projects overplaying their hand and insisting they own certain words or ideas that they have no real claim to, particularly when there isn't any actual chance of confusion. The Firebird renaming wasn't so much sensible precedent as a good example of a Mozilla saying "okay please stop yelling, we'll do whatever you want".
Indeed, except that this project has nothing to do with i18n like (most of) the other projects you are citing. This is a compiler project, not a multilinguistic project.
2) There is nothing called "Python Babel", it's just called "Babel".
Eclipse Babel (https://eclipse.org/babel/) is called "Eclipse Babel" so there is no name clash.
For some of the other projects, you have a (minor) point.
3) "The Firebird renaming wasn't so much sensible precedent as a good example of a Mozilla saying "okay please stop yelling, we'll do whatever you want"."
Mozilla had a much stronger reason to comply than just goodwill and being fair: the other party had a trademark (see: http://www.firebirdsql.org/en/firebird-brand-faq/ ).
4) The considerate thing to do would have been to call the project "Babeljs".
However, TypeScript's goals aren't as different as you might think. It is a strict superset of JavaScript, and although it adds features that are not yet on the standards track, there are proposals to add optional static typing via annotations to JS. Given that Google are also interested in such a capability, given Dart and AtScript, it seems probable that types will eventually become part of the language.
6to5 (now Babel) compiles javascript with Ecmascript 6 and 7 features (poorly supported) to JavaScript code that only uses Ecmascript 5 features (which all major browsers since 2011 have supported).