What was done
wsbsd is a window server that speaks the message layout of macOS's WindowServer (SkyLight), plus a compatibility layer, so Mac apps such as Hex Fiend build and run on FreeBSD.
wsbsd compiles unmodified open source macOS (Cocoa and AppKit) applications from GitHub on FreeBSD and runs them on a window server that speaks the message layout of macOS's WindowServer (SkyLight). It uses no X11, no Wayland and no Apple binaries. Its commits are co-authored by Claude Sonnet 5.5.
How it was done
The window server wsd is written in C99 and implements the SkyLight wire protocol (about 270 of 728 routines have real handlers), with a software and OpenGL ES compositor, input and VNC output. A GNUstep backend and a compatibility SDK add the AppKit, Foundation and CoreServices APIs that modern Mac sources expect. A small Xcode build driver reads .xcodeproj files and makes app bundles. The rule is that upstream sources are never edited.
Results
As of 2026-10-17 on FreeBSD 14.5, Hex Fiend builds (framework 61 of 61 files, app 47 of 47, with four Swift files ported in an overlay) and runs with hex and ASCII columns. Pashua builds unmodified (41 of 41) and runs. GrandPerspective starts but fails when a scan begins. CI runs unit, sanitizer and fuzz tests.