Start of a thread on the TUHS mailing list mentioning the japanese project https://github.com/ryomuk/TangNanoDCJ11MEM/tree/main
Memory system and UART implemented on Tang Nano 20K FPGA for DEC DCJ11 PDP-11 Processor.

The blog has also a number of articles about pdp-11.

An EMACS command compatible editor for PDP/RSX and VAX/VMS systems with TECO version 35 (or later).

Information  about a macroassembler for pdp-11 running v7 unix.

The Amsterdam Compiler Kit is a cross-platform compiler and toolchain suite that is small, portable, extremely fast, and extremely flexible. It targets a number of low-end machines including the Z80, 8086 and 80386, but there are many other code generators available. It supports several languages, including ANSI C, Pascal and Modula-2, and contains integrated runtime libraries including a libc.

The maintainer, David Given states "I, dtrg, cannot honestly recommend using the ACK for production code unless as a stop-gap measure or unless the other benefits of the ACK (e.g. having a very lightweight turnkey toolchain is valuable to you) outweigh the code quality."

This this thread is branching off topic anyway, I'll just quickly
mention that I'm currently working on "Small ITS".  An ITS-like
operating system for the MIT Logo group PDP-11/45.  "PDP-11" <- see,
almost back on topic.  Sorry, those who are curious may contact me
privately.

Guides how to install or run older UNIX versions in simh.
Also the UNIX Programmer's manual of V1-V6. V1-V6 are available as nroff output converted to html. V4-V6 are also available as troff'ed PDFs.
The site also has information about Plan 9 and pdp-6/pdp-10.

Interesting information about using the GPU of the Raspberry π.
In the forum thread https://stardot.org.uk/forums/viewtopic.php?p=152451#p152451 emulators for 6502 and other processors are discussed, even pdp-11 was mentioned.
More details can be found at https://github.com/hoglet67/PiTubeDirect/wiki
The pdp-11 emulator is in the 'egg-eater-dev' branch.

The project contains the VHDL code for a complete DEC PDP-11 system: a PDP-11/70 CPU with memory management unit, but without floating point unit, a complete set of mass storage peripherals (RK11/RK05, RL11/RL02, RK70/RP06, TM11/TU10) and a basic set of UNIBUS peripherals (DL11, LP11, PC11), and last but not least a cache and memory controllers for SRAM and PSRAM.

The design is FPGA proven, runs currently on Digilent Cmod A7 , Arty , Basys3 , Nexys4 DDR , Nexys4 , Nexys3 , Nexys2 and S3board boards. See section Complete Systems for more information.

5th Edition UNIX, 7th Edition UNIX, and 2.11BSD UNIX are known to boot, the hardware should also support DEC RT11 and RSX-11M, see section Running Systems for more information.

This is a retrocomputing project, rebuilding hardware from the late 70s and running historical software. To get into the tune see Figure D-1, a 11/70 console, and Figure F-2, a baseline system setup.

Another pdp-11 simulator written in Javascript.
https://www.pcjs.org/software/dec/pdp10/tapes/ was mentioned in 2023-09 on alt.sys.pdp10.