The seminal book: <a href="http://www.jsoftware.com/papers/APL.htm">A Programming Language</a>.
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<a href="http://www.jsoftware.com/papers/tot.htm">Notation as a Tool of Thought</a> is an idea which continues to guide and motivate the development and use of APL notation.
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<a href="http://archive.vector.org.uk/art10008110">Article in <i>Vector</i> on array-programming languages by Keith Smillie.
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<a href="http://www.jsoftware.com/papers/FPL.htm">Formalism in Programming Languages</a> by Kenneth E. Iverson.<br>
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Presented at a Working Conference on Mechanical Language Structures, Princeton, N.J., August 1963, sponsored by the Association for Computing Machinery, the Institute for Defense Analyses, and the Business Equipment Manufacturers Association. <br>
[From the introduction] <br>
Although the question of equivalences between algorithms expressed in the same or different languages has received some attention in the literature, the more practical question of formal identities among statements in a single language has received virtually none. The importance of such identities in theoretical work is fairly obvious. The present paper will be addressed primarily to the practical implications for a compiler.  <br>
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<a href="http://cosy.com/language/APLBlos/APLBLOSS.TXT">"APL Blossom Time" lyrics</a> and
recordings: a <a href="source/APL_Blossom_Time_Studio.mp3">studio version</a> and <a href="source/APL_Blossom_time_Live.mp3">a live version</a> from APL81 in San Francisco. <br>
Michael Montalbano explains this song in <a href="http://www.ed-thelen.org/comp-hist/APL-hist.html">his "A Personal History of APL"</a>.
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<a href="http://www.leonardo.info/gallery/burningman_fire/breed.html.">Larry Breed's chaotic fireball at Burning Man</a>
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<a href="http://www.ed-thelen.org/comp-hist/APL-hist.html">Michael Montalbano's "A Personal History of APL"</a>
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<a href="source/ibmrd1704F.pdf">The Design of APL</a> by Adin Falkoff and Ken Iverson. <br>
<a href="http://www.jsoftware.com/papers/APLDesign.htm">HTML version</a>
<b>Abstract:</b> This paper discusses the development of APL, emphasizing and illustrating the principles underlying its design. The principle of simplicity appears most strongly in the minimization of rules governing the behavior of APL objects, while the principle of practicality is served by the design process itself, which relies heavily on experimentation. The paper gives the rationale for many specific design choices, including the necessary adjuncts for system management. <br>
From the introduction: This paper attempts to identify the general principles that guided the development of APL and its computer realizations, and to show the role these principles played in the evolution of the language. The reader will be assumed to be familiar with the current definition of APL [1]. A brief chronology of the development of APL is presented in an appendix.
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<a href="http://www.rexswain.com/aplinfo.html">Rex Swain's APL information page</a>.
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Stevan Apter's<a href="http://www.nsl.com/">"No Stinking Loops" page</a> provides links to numerous languages that allow loopless programming.
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<a href="http://www.jsoftware.com/papers/APLQA.htm">APL Quotations and Anecdotes</a> as collected by Roger Hui.
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<a href="http://www.jsoftware.com/papers/">Extensive list of papers on APL</a>.
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<a href="http://www.jsoftware.com/papers/APLDictionary.htm">A Dictionary of APL</a> spells out a comprehensive rationalization of APL which was another step in the development of J.
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<a href="http://www.jsoftware.com/papers/commentary.htm">A Commentary on APL Development</a> further develops and explors ideas from "Rational APL" and "A Dictionary of APL".
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