The limited cross-linker for MACRO11 PDP-11 assembler (gzipped sources, 2K), it can't be directly used from Microsoft Windows — see note.

Notepad+4, БK0011 edition

Reduced Basic cross-compiler

32/64-bit Xlife ported to 8/16-bit world!

The number π calculator is here (the sources are included). The archive contains versions for the БK0010, БK0011, RT-11, and RSX-11.