A+
Morgan Stanley's APL with GUI, system interfaces, callbacks, synchronization among objects, ASCII and/or APL character sets. Manual, history, screenshots, downloads, documents, FAQ, contacts, resources, reviews. [Open Source, GPL]
APL2000 Inc.
Rapid Application Development products and services. Announcements, support.
APL2C
An extended APL interpreter with built in compiler, able to convert APL functions into C source files. The generated C code is portable and can be compiled on multiple platforms. Nested arrays, APL symbols, and new style control structures.
CoSy/K/CoSy
The K.CoSy "noteComputing" environment. An Open vocabulary creating an interactive programming environment for Arthur Whitney's K language. Development of scalable quantitative hierarchical systems as rapidly as the task can be defined.
Dyalog Limited
Producers of one of the finest APL interpreters for all versions of Windows and some flavours of UNIX. They have links to an APL webserver producing graphs.
J Software
Modern high performance, general purpose programming language, ideal for complex analytics and data manipulation. APL inventor Kenneth Iverson formed Iverson Software and works here. Free evaluation download.
Juggle: J for Unix
Master distribution point for Unix versions of ISI's J system and related issues. Features: bug report database, J Feature Hitlist, CVS repository for official and contributed J code, mailing lists, ISI site mirror.
Kx Systems
Makers of Kdb relational database manager extended for timeseries, and K programming development environment. Mission-critical applications are being built in Kdb and K at top-tier financial institutions world-wide.
MicroAPL Ltd
Innovative porting tools and services, and software consulting. Sells APL.68000 for Apple Macintosh. Recently released APLX for Windows, MacOS, Linux & AIX.
Soliton Associates
Delivers systems and applications software products for IBM/MVS, and now RISC/UNIX platforms, integrated with proprietary and industry-standard middleware. Also a free Linux version.
STSC APL*PLUS, Other APLs, and Some Utilities
APL Returns to the Mac. Medium-long review; vendors, contact information, code examples, screenshot. [MacTech]