COL (Correcteur Orthographique de Latin) is a free tool providing assistance to check the spelling of a Latin text. Available for Microsoft Word, LibreOffice, OpenOffice.org and AbiWord, it includes a dictionary of about 400,000 Latin forms (classical and medieval Latin).
To best match the different practices, COL is configurable: the user can select a particular spelling (how to represent diphthongs, vowels u and i...). It works exactly like spellcheckers of other languages: when a word is not in the dictionary, it is underlined in red. More Info »
This spellchecker is obviously not intended to be exhaustive, nor it wants to "normalize" the spelling of Latin. It was created primarily as an aid to save time and facilitate the work of all those who need to understand Latin texts (for the transcription of manuscripts, for example), but also to fix correct Latin texts scanned and processed by OCR, usually with many faults.