LXGW WenKai

The most moving CJK kai of the open-source community. Built on Klee One - Fontworks' Japanese OFL face - by contributor lxgw, who refitted, extended and tuned it into a 20,000-plus-hanzi family balancing brush-script soul and the slender bone of fangsong. Its ecosystem is enormous: three weights (Light/Regular/Medium), a GB cut following mainland standard forms, a TC cut preserving traditional-character heritage, a Screen variant hardened for displays, a Mono edition that programmers adore, and a half-size Lite. The GB build covers the State Standard character table and stands with Source Han and Noto as the three open-source CJK workhorses - proof that a one-person charity typeface can run serious production.

E-readers and long-form articles (kai fatigue is lower here than anywhere), courseware, heritage and lifestyle brands, humane empty-states and pull quotes in UI, and code editors via Mono. Picks: Regular body, Medium heads, Light on paper-tint backgrounds; in print its faces run slightly small against Source Han, compensate 3-5 %. On the web, the TC build is one Google Fonts link away; self-hosting the GB cut means subsetting it yourself.

Licence：SIL Open Font License 1.1

The dominant permissive licence for open fonts: free commercial use, modification, embedding and redistribution. Its core duties are that derivatives stay under OFL without the Reserved Font Name, the licence text travels with the files, and the fonts themselves are never sold standalone. Works typeset with them belong wholly to you.

SIL OFL 1.1: free commercial use, embedding, modification and redistribution, with the standard duties - derivatives stay OFL, reserved names come off, files are never sold standalone, OFL.txt travels with every distribution. 'LXGW / 霞鹜' is a Reserved Font Name and must not survive into modified releases; the README also credits upstream Klee One to FONTWORKS. The full licence lives in the repo - top-tier stability among open fonts.