Inqlude provides a comprehensive listing of all existing libraries for developers of applications using the Qt toolkit. Inqlude is run by the community and open for contributions.
Support for spellchecking
Sonnet is a plugin-based spell checking library for Qt-based applications. It supports several different plugins, including HSpell, Enchant, ASpell and HUNSPELL.
It also supports automated language detection, based on a combination of different algorithms.
The simplest way to use Sonnet in your application is to use the SpellCheckDecorator class on your QTextEdit.