Hacker News Reader

... not only for Linux and Windows.

Geany is known to run under: Linux FreeBSD (and HardenedBSD / GhostBSD) NetBSD OpenBSD MacOS X AIX Oracle Solaris Illumos (OpenIndiana) Windows

Indeed, it's my go-to GUI text editor on every platform I use (apart from Haiku OS, though it isn't a daily use OS yet).