This package comes with both a theme and a syntax lexer.

To install, copy lexers/moonscript.lua to a lexers directory in your local textadept directory (usually .textadept).

To install the theme copy themes/moon.lua to a themes directory in your local textadept directory.

Update your init.lua:

-- enable the lexer
local file_types = require "textadept.file_types"
file_types.extensions.moon = "moonscript"

-- enable the theme, with a custom font (optional)
ui.set_theme(CURSES and "term" or "moon", {
	font = "Source Code Pro",
	fontsize = 14,
})