If you have tried using the the TinyMCE spell check plugin on UTF-8 encoded page with the PSpellShell adapter you probably noticed that the implementation is broken. The spelling suggestions do not contain properly encoded UTF-8 characters.
Since the creators of TinyMCE moved to Github it was a great opportunity to try and push these changes to the master branch. If you need this you can look at the changes that need to be made to the PSpellShell adapter or just clone my fork of the spellcheck plugin.
p.s. Have I mentioned how awesome Git and Github are?