APL-sharp

APL# (pronounced APL Sharp) was presented by Dyalog Ltd. at the 2010 APL conference in Berlin. The goal was to make the benefits of safe/managed computing available to users of APL through the development of an APL dialect targeting Microsoft Silverlight/Moonlight and featuring tight integration with Microsoft .NET.

APL# was to be a new dialect of APL designed with object-oriented/language-agnostic platforms in mind, using Microsoft .NET as the initial target platform. Although portability of old APL code to APL# was an important consideration, the fact that complete upwards compatibility with "classic" APL was not achievable allowed an attempt to tidy up a few other aspects of APL. The goal was to produce a language which was as powerful a Tool of Thought as classic APL and APL2, at the same time as feeling significantly more acceptable to a software engineer.

However, taking full advantage of the shared type system and related services which forced the abandoning some of the most central dogma of "classic" APL interpreters:


 * The notion that APL only has two data types: numbers and characters
 * That arguments are always passed "by value"
 * User-defined names are global by default, and local variables are visible to all sub-functions

APL# featured a single functional form (besides for trains) which was a hybrid between dfn and tradfn syntax, superficially resembling that of dfns, but allowing a header (calling signature) and control structures.

In 2012 Microsoft deprecated Silverlight for HTML5 in Windows 8, and Dyalog subsequently abandoned the APL# project.

2010 APL conference

 * APL# - an APL for Microsoft.Net
 * Unifying T-Fns and D-Fns in APL#

2011 Dyalog user meeting

 * APL# Language Description
 * APL# Core language