Ispell
Encyclopedia
Ispell is a spelling checker for Unix
that supports most Western languages. It offers several interfaces, including a programmatic interface for use by editors such as emacs
. Unlike GNU Aspell
, ispell will only suggest corrections that are based on a Damerau–Levenshtein distance of 1; it will not attempt to guess more distant corrections based on English pronunciation rules.
Ispell has a very long history that can be traced back to
a program that was originally written in 1971 in PDP-10
Assembly language
by R.E.Gorin, and later ported to the C programming language
and expanded by many others.
It is currently maintained by Geoff Kuenning.
The generalized affix description system introduced by ispell has since been imitated by other spelling
checkers such as MySpell
.
Like most computerized spelling checkers, ispell works by reading an input file word by word, stopping when a word is not found in its dictionary. Ispell then attempts to generate a list of possible corrections and presents the incorrect word and any suggestions to the user, who can then choose a correction, replace the word with a new one, leave it unchanged, or add it to the dictionary.
Ispell pioneered the idea of a programming interface
, which was originally intended for use by emacs
. Other applications have since used the feature to add spell-checking to their own interface, and GNU Aspell
has adopted the same interface so that it can be used with the same set of applications.
There are ispell dictionaries for most widely-spoken Western languages.
Ispell is available under a specific Open Source
license.
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
that supports most Western languages. It offers several interfaces, including a programmatic interface for use by editors such as emacs
Emacs
Emacs is a class of text editors, usually characterized by their extensibility. GNU Emacs has over 1,000 commands. It also allows the user to combine these commands into macros to automate work.Development began in the mid-1970s and continues actively...
. Unlike GNU Aspell
GNU Aspell
GNU Aspell, usually called just Aspell, is a free software spell checker designed to replace Ispell. It is the standard spell checker for the GNU software system. It also compiles for other Unix-like operating systems and Windows. The main program is licensed under the GNU Lesser General Public...
, ispell will only suggest corrections that are based on a Damerau–Levenshtein distance of 1; it will not attempt to guess more distant corrections based on English pronunciation rules.
Ispell has a very long history that can be traced back to
a program that was originally written in 1971 in PDP-10
PDP-10
The PDP-10 was a mainframe computer family manufactured by Digital Equipment Corporation from the late 1960s on; the name stands for "Programmed Data Processor model 10". The first model was delivered in 1966...
Assembly language
Assembly language
An assembly language is a low-level programming language for computers, microprocessors, microcontrollers, and other programmable devices. It implements a symbolic representation of the machine codes and other constants needed to program a given CPU architecture...
by R.E.Gorin, and later ported to the C programming language
C (programming language)
C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
and expanded by many others.
It is currently maintained by Geoff Kuenning.
The generalized affix description system introduced by ispell has since been imitated by other spelling
checkers such as MySpell
MySpell
MySpell was the former spell checker included with OOo Writer of the free OpenOffice.org office suite.Since version 2.0.2 OpenOffice.org has replaced MySpell with Hunspell.-Background:...
.
Like most computerized spelling checkers, ispell works by reading an input file word by word, stopping when a word is not found in its dictionary. Ispell then attempts to generate a list of possible corrections and presents the incorrect word and any suggestions to the user, who can then choose a correction, replace the word with a new one, leave it unchanged, or add it to the dictionary.
Ispell pioneered the idea of a programming interface
Application programming interface
An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...
, which was originally intended for use by emacs
Emacs
Emacs is a class of text editors, usually characterized by their extensibility. GNU Emacs has over 1,000 commands. It also allows the user to combine these commands into macros to automate work.Development began in the mid-1970s and continues actively...
. Other applications have since used the feature to add spell-checking to their own interface, and GNU Aspell
GNU Aspell
GNU Aspell, usually called just Aspell, is a free software spell checker designed to replace Ispell. It is the standard spell checker for the GNU software system. It also compiles for other Unix-like operating systems and Windows. The main program is licensed under the GNU Lesser General Public...
has adopted the same interface so that it can be used with the same set of applications.
There are ispell dictionaries for most widely-spoken Western languages.
Ispell is available under a specific Open Source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
license.