1 Introduction

GNU Aspell is a spell checker designed to eventually replace Ispell. It can either be used as a library or as an independent spell checker. Its main feature is that it does a much better job of suggesting possible replacements for a misspelled word than just about any other spell checker out there for the English language. Unlike Ispell, Aspell can also easily check documents in UTF-8 without having to use a special dictionary. Aspell will also do its best to respect the current locale setting. Other advantages over Ispell include support for using multiple dictionaries at once and intelligently handling personal dictionaries when more than one Aspell process is open at once.

The latest version of Aspell can always be found at http://aspell.net

1.1 Comparison to other spell checker engines

The Suggestion Intelligence is based on a small test kernel of misspelled/correct word pairs. Go to http://aspell.net/test/cur/ for more info and how you can help contribute to the test kernel.

If you have any other information you would like to add to this chart please contact me at kevina@gnu.org.

1.1.1 Comparison to Ispell

1.1.1.1 Features that only Aspell has

• Is an actual library that other programs can link to instead of having to use it through a pipe.
• Does a much better job of suggesting possible replacements for a misspelled word than Ispell does or for that matter many other spell checkers I have seen. If you know a spell checker that does a better job please let me know.
• Can learn from user’s misspellings.
• Can easily check documents in UTF-8 without having to use a special dictionary.
• Has support for using multiple dictionaries at once.
• Is multiprocess intelligent. When a personal dictionary (or replacement list) is saved, it will now first update the list against the dictionary on disk in case another process modified it.
• Can share the memory used in the main word list between processes.
• A better, more complete word list for the English language. Word lists are provided for American, British, and Canadian spelling. Special care has been taken to only include one spelling for each word in any particular word list. The word list included in Ispell by contrast only included support for American and British and also tends to included multiple spellings for a word which can mask some spelling errors.

1.1.1.2 Things that, currently, only Ispell has

• Lower memory footprint
• Ability to deal with arbitrary multi-character letters such as old ASCII encodings of accented letters.
• Perhaps better support for spell checking (La)TeX files.

For a detailed description of how Aspell differs from Ispell, See Differences From Ispell.

1.1.2 Comparison to Hunspell

Hunspell is based on Myspell. Myspell was created as a simple spell checker for use in OpenOffice. Myspell’s affix support was merged into Aspell 0.60 so Hunspell and Aspell can use the same affix file to some extent.

Hunspell has better support for language peculiarities including compounding and complex morphology. However the Hunspell (v1.7.0) utility currently has problems with apostrophe (') in words.

Aspell generally has better suggestions for non-phonetic languages such as English and French. Aspell suggestion speed also tends to be significantly faster than Hunspell. For a compression of suggestion quality and speed see http://aspell.net/test/.