esm

mlly vs acorn: 0.046 ms vs 0.017 ms findExports

tsup vs unbuild: Should You Switch? 931ms vs 2034ms

tsup 8.5.1 vs unbuild 3.6.1 on a 150-module TypeScript library (ESM+CJS): median 931 ms vs 2034 ms (~2.2x); with .d.ts 3213 ms vs 3740 ms (~1.16x). unbuild ESM 4.9% smaller, CJS 8.3% smaller; tsup README says not actively maintained.

Should You Leave Rollup? 964ms vs 246ms

Rolldown 1.2.12 vs Rollup 4.64.0 on 501 ESM files (197380 B source): median wall 245.617 ms vs 964.3 ms (~3.9x). Output 130522 vs 126894 B. Direct node bin, 5 interleaved warm runs, no minify.

Webpack 5.111: ESM output stable, output.copy, CSS targets (14 Sep 2026)

On 14 September 2026 webpack published the 5.111 blog: ES module output is stable (drop experiments.outputModule; keep/set output.module), output.copy copies public/static files into the build, browserslist-aware CSS lowering/color fallbacks expand, performance hint options rename, acorn/neo-async removed as deps, plus hot-update/cache fixes. npm latest as of 5 Oct 2026 research is 5.111.1 (5.111.0 shipped 14 Sep). ShopperCove docs checklist only; no affiliate.