1. Introduction

Aspell is an Open Source spell checker designed to eventually replace Ispell. Its main feature is that it does a much better job of coming up with possible suggestions than Ispell does. In fact recent tests shows that it even does better than Microsoft Word 97's spell checker in some cases. In addition it has both compile time and run time support for other non-English languages. Aspell is also a library however the recommend way to use aspell is through the Pspell library as the actual interface to the aspell library is constantly changing.

1.1 The Future of Aspell

Aspell .33.7 is most likely going to be the last official version of Aspell as in the near future Aspell is going to be merged into Pspell:

From: Kevin Atkinson
To: aspell-announce, pspell-announce
Date: 08/01/2001
Subject: Aspell and Pspell will be merged.

In the near future Aspell is going to be merged into Pspell. This will happen with the next major release of Pspell. If everything goes as planed, in the next major version of Pspell:

• Aspell will be included as part of Pspell as a module
• The Ispell module will also be included
• Most of the functionally of the Aspell command will be replaced with a new Pspell command which will work for any spell checker
• The English dictionary will no longer be included with Aspell. Instead it will be part of the Aspell-dicts package
• The manuals will be switched over from LyX/L^ATEX to LyX/DocBook so that in can easily be converted to other formats such as info and man.
• The current C++ interface may disappear and be replaced with a nicer C++ interface which will act as a wrapper for the C interface as I discussed earlier. If you are currently using the C++ interface and this will create a major problem for you please let me know.

This will require major reorganization of just about anything associated with Aspell and Pspell which will probably require packagers to redo there packaging scheme for Aspell and Pspell as some libraries and data files will disappear, other will be created, and the location of some of the data files will be moved. Also, as mentioned above Aspell, as you know it know, is going to disappear and be replaced with a generic utility. Some Aspell specific things, such as creating dictionaries, will remain in the Aspell utility however the executable will be renamed to aspell-util to avoid any confusion.

Also, the Aspell sourceforge project might disappear, however I am not sure about this. At very least the Aspell mailing lists and bug tracker will disappear to avoid confusion on where question and bug reports should be posted.

All of this should happen around the end of August.

1.2 Comparison to other spell checker engines

	Aspell	Ispell	Netscape 4.0	Microsoft Word 97
Open Source	x	x
Suggestion Intelligence	88-98	54	55-70?	71
Personal part of Suggestions	x	x	x
Alternate Dictionaries	x	x	?	?
International Support	x	x	?	?

The suggestion Intelligence is based on a small test kernel of misspelled/correct word pairs. Go to http://aspell.sourceforge.net/test for more info and how you can help contribute to the test kernel. The current scores for aspell are 88 in fast mode, 93 in normal mode, and 98 in bad spellers mode see section 5.4.5 for more information about the various suggestion modes.

If you have any other information you would like to add to this chart please contact me at kevina at users sourceforge net.

1.2.1 Comparison to Ispell

1.2.1.1 Features that only Aspell has

• Does a much better job with coming up with suggestions than Ispell does or for that matter any other spell checker I have seen. If you know a spell checker that does a better job please let me know.
• Can learn from users misspellings.
• Is an actual library that others programs can link to instead of having to use it through a pipe.
• 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.
• Support for detachable dictionaries so that more than one aspell class can use the same dictionary.
• Support for multiple personal dictionaries as well as support for special auxiliary dictionaries.
• Better support for run-together words.
• Ability to use multiple dictionaries by simply specifying it on the command line or in the configuration files.

1.2.1.2 Things that, currently, only Ispell have

• Lower memory footprint
• Support for affix compression
• Perhaps better support for spell checking (La)TEX files.
• Support for spell checking Nroff files.