Third-party licenses

Patter and its tools are open source and MIT-licensed. They also bundle a few third-party components that keep their own licenses; the notable ones are collected here.

Spell-check dictionaries and engine

The built-in English dictionaries come from SCOWL / the English Speller Database, under a permissive BSD/MIT-style license (attribution only). The spell-checking engine is nspell (MIT). Any Hunspell dictionaries you import yourself keep their own licenses; that’s between you and wherever you got them. See Spell-check for how these are used.