Ispell is a spelling checker for

Unix Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

that supports most Western languages. It offers several interfaces, including a programmatic interface for use by editors such as

Emacs Emacs (), originally named EMACS (an acronym for "Editor Macros"), is a family of text editors that are characterized by their extensibility. The manual for the most widely used variant, GNU Emacs, describes it as "the extensible, customizable, s ...

. Unlike

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 operating system. It also compiler, compiles for other Unix-like operating systems and Microsoft Win ...

, ispell will only suggest corrections that are based on a

Damerau–Levenshtein distance In information theory and computer science, the Damerau–Levenshtein distance (named after Frederick J. Damerau and Vladimir I. Levenshtein.) is a string metric for measuring the edit distance between two sequences. Informally, the Damerau–Lev ...

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 Digital Equipment Corporation (DEC)'s PDP-10, later marketed as the DECsystem-10, is a mainframe computer family manufactured beginning in 1966 and discontinued in 1983. 1970s models and beyond were marketed under the DECsystem-10 name, especi ...

Assembly language In computing, assembly language (alternatively assembler language or symbolic machine code), often referred to simply as assembly and commonly abbreviated as ASM or asm, is any low-level programming language with a very strong correspondence bet ...

by R. E. Gorin, and later ported to the

C programming language C (''pronounced'' '' – like the letter c'') is a general-purpose programming language. It was created in the 1970s by Dennis Ritchie and remains very widely used and influential. By design, C's features cleanly reflect the capabilities of ...

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 is a free spell checker, written to explore how affix compression could be implemented. It used to be included with the OpenOffice.org office suite and Mozilla client software, and was replaced with the more powerful Hunspell library betw ...

. 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 An application programming interface (API) is a connection between computers or between computer programs. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how to build su ...

, which was originally intended for use by Emacs. Other applications have since used the feature to add spell-checking to their own interface, and

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 Open-source licenses are software licenses that allow content to be used, modified, and shared. They facilitate free and open-source software (FOSS) development. Intellectual property (IP) laws restrict the modification and sharing of creative ...

References

External links

*
Original unix spell, on which Ispell is based
Spell checkers Free spelling checking programs Language software for Linux Unix software {{unix-stub

See also

References

External links