APL is an acronym for A Programming Language - it is based on a strict (unambiguous) mathematical notation invented by the late Kenneth E Iverson; it is an interpreted, interactive, and array oriented commercial language available for all contemporary platforms. Amongst programming languages, APL has at least three unique/exclusive hallmarks:

1. It is culture 'neutral'; it uses symbols rather than 'reserved' keywords.

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2. It is solution 'focussed'; it promotes the expression of algorithms without any consideration of machine architecture or operating system - APL is a type 'inferred' language that rarely necessitates coding structures for loops.

3. It has just one 'simple' operator precedence rule: all expressions evaluate from right to left; if necessary, this default can be overrridden by enclosing parts of an expression in round brackets, with innermost sets of brackets imposing the highest level of precedence.

APL is one of the oldest programming languages, and an important influence on the development of spreadsheets, functional programming[1], Mathematica and MatLab[2]. It is a dynamic, interpreted language based on Iverson's mathematical notation. All data are arrays. Primitive operations all extend to arrays, and are denoted by distinctive graphic symbols rather than words, making APL programs compact and visually striking, with few or no loops.

The language flourishes in scientific, actuarial, statistical and financial applications, and is favored by domain experts writing software for their own purposes. APL is also associated with rapid and lightweight development projects in volatile business environments.

#!wiki comment Flourishing?! Certainly not. APL is still used in... or APL is used in... seems to me much more appropriate.

Favoured by Domain Experts?. Certainly not. There is a whole range of programming languages available which focus on that. Some of them are quite successful. Almost all of them are more successful than APL in total.

The Wikipedia article about this (see http://en.wikipedia.org/wiki/Domain_specific_language) mentions APL: Although notorious for its use of Greek letters and special symbols, the APL programming language, with its interactive session, provided for rapid design and deployment of interactive and scriptable domain specific languages. These usually, by design, required no special input consideration from its users such as APL keyboards or fonts.

The first sentence is gramatically incorrect. Both sentences make no sense. Worse, these sentences are located under the caption "Unix Shell Scripts". -- KaiJaeger 2009-07-26 08:04:22 }}}

Interpreters are available for a wide range of platforms including PCs, Macs, Linux, mainframes and hand-held computers. Recent Notable extensions to APL interpreters and IDEs include:

#!wiki comment But this is not a feature of APL as such! It is a matter of implementation. In other words, it should not be mentioned here at all.

Otherwise the two things should not be summarized under one topic: OO and .NET are in this context two different things.

#!wiki comment What exactly is a "native language" in this context? What means "hosted"?

Visual APL is so fundamentally different from others (I dare say: real!) APLs that it needs much more details - or shouldn't be mentioned at all! -- KaiJaeger 2009-07-26 08:04:22

#!wiki comment Again: this is implementation stuff. The word "seamlessly" is hard to justify in a Wikipedia article anyway. It works when the type declarations delivered by the authors of the COM thing are correct. If not it won't. Often they are not, including some from Microsoft.

#!wiki comment What I am missing is a remark about the most important enhancements: Namespaces in Dyalog and integrated debuggers in some implementation. This is again implementation stuff, but very closely related with the language and it's usage. -- KaiJaeger 2009-07-26 08:04:22

-- StephenTaylor 2009-07-25 05:36:32

[1] http://awards.acm.org/citation.cfm?id=0703524&srt=all&aw=140&ao=AMTURING
[2] http://www.mathworks.com/company/newsletters/news_notes/clevescorner/jan06.pdf