J came along particularly to fix the ASCII problem, but it took some design decisions for things that were bugging Ken Iverson from years of APL work, that var[

J came along particularly to fix the ASCII problem, but it took some design decisions for things that were bugging Ken Iverson from years of APL work, that var[4] style indexing is really a function application, that all functions should have configurable “rank”, that tacit programming with trains of functions should be a focus, among other things. Many of those choices have been added to Dyalog APL since then, SQUAD indexing function, trains, rank adjustment operator. Dyalog APL has traditional APL functions and keywords which looks a lot more procedural than the golfed symbols mostly shown - for loops, if statements, etc. which GNU APL has not, IIRC; and has an object system :Class and a bridge to the .Net framework and C# interop both ways, GUI support possible through that (Windows Forms I think).