i

re APL: BQN is a new take on APL w/ high performance implementation https://mlochbaum.github.io/BQN/ Dyalog APL is a well supported proprietary APL implementation https://www.dyalog.com re open source k implementations: there are many by now here is a current non-exhaustive list grouped by k dialect they orbit (to my understanding) k9 ktye (Go w/ Go, wasm, C targets) https://github.com/ktye/i k6 ngn/growler (C): https://codeberg.org/growler/k oK (JavaScript): https://github.com/JohnEarnest/ok kiwi (Zig): https://github.com/kiwi-array-lang/kiwi k3 kona (C): https://github.com/kevinlawler/kona gk (C): https://github.com/cmh25/gk ksharp (C#): https://github.com/ERufian/ksharp k-like goal (Go): https://codeberg.org/anaseto/goal klongpy (Python) https://github.com/briangu/klongpy I'm working on kiwi. kiwi has a focus on supporting Apple Silico

Other than ngn/k ... https://ktye.github.io/kdoc.htm https://github.com/ktye/i/releases/download/latest/k.c IIRC, some old UNIX versions had an APL interpeter in the userland. For me, a k interpreter could be the ultimate UNIX utility. But interoperability with pipes and other UNIX utilities is awkward to say the least, as is having to use other programming languages as duct tape.

across architectures: you're right, as of now it's x86_64 only across operating systems: it works on linux and freebsd as-is (thanks bakul), and with a few changes on windows+libc (thanks ktye) - https://github.com/ktye/i/tree/master/_/ngn though i personally never use windows