Does Qt have an implementation of spell checking? Or maybe some ready-to-use things for text widgets? I also would like to use dictionaries for various languages if possible.
No implicit in Qt, but it is really easy to implement.
You can take a look at this both examples:
In Python: http://john.nachtimwald.com/2009/08/22/qplaintextedit-with-in-line-spell-check/
In C++ (extending QTextEdit to enable SpellChecking): http://qt-apps.org/content/show.php/Online+spell+check+editor?content=77339