There are 5 repositories under rsx-11 topic.
RSX-11M-like OS for the Z280 CPU.
A RSX-11M-like multi-tasking OS for the Z180.
tvx: TVX is a portable full-screen editor for CP/M, MS-DOS, GEMDOS, RT-11, RSX-11, VAX/VMS, and UNIX, written in C by Bruce E. Wampler
emacs11: EMACS11 (for PDP/RSX and VAX/VMS) in TECO-11 by Fred Fish
Port of Nils M Holm's T3X/Z compiler to RSX180 and RSX280.