看到 jQuery 的公告「jQuery 4.0.0 BETA!」這篇，有種「啊，居然」的感覺冒出來...
要注意這個版本放掉了 IE10 以及更早的版本，但還是有支援 IE11，目前計畫到 jQuery 5.0 才會拔掉：
jQuery 4.0 drops support for IE 10 and older. Some may be asking why we didn’t remove support for IE 11. We plan to removes support in stages, and the next step will happen in jQuery 5.0.
另外一個頗大的改變是 source 端改成 ES module 了，這樣對 jQuery 團隊開發上應該會方便不少 (很多現代工具的引入)：
jQuery source migrated to ES modules
It was a special day when the jQuery source on the main branch was migrated from AMD to ES modules. The jQuery source has always been published with jQuery releases on npm and GitHub, but could not be imported directly as modules without RequireJS, which was jQuery’s build tool of choice. We have since switched to Rollup for packaging jQuery. And we also run tests on the ES modules before packaging them.
這有種古蹟改建的味道啊...