---OPERATING SYSTEMS WRITTEN IN ASSEMBLER---
KolibriOS
https://kolibrios.org/en/
32 bits operating system
MenuetOS
http://www.menuetos.net/
32 and 64 bits operating system
BareMetalOS ( frozen project??? )
https://gitlab.com/ReturnInfinity/BareMetal-OS
64 bits operating system
Snowdrop OS
http://sebastianmihai.com/snowdrop/
a homebrew 16-bit operating system from scratch, in assembly language
DS-OS
http://www.itfromterabit.net/dsos/
is a free operating system with open source written entirely in 8086 assembly using the A86 assembler
---ASSEMBLER LANGUAGES---
Flat assembler FASM
http://flatassembler.net/
Netwide Assembler NASM
https://www.nasm.us/
Open Watcom Assembler WASM
https://github.com/open-watcom/open-watcom-v2
http://www.japheth.de/JWasm.html
GNU Assembler GAS
https://debrouxl.github.io/gcc4ti/gnuasm.html
https://www.st.com/content/ccc/resource/technical/document/user_manual/group1/fb/cb/d6/71/03/25/42/a1/UserManual_GNU_Assembler/files/UserManual_GNU_Assembler.pdf/jcr:content/translations/en.UserManual_GNU_Assembler.pdf
YASM
http://yasm.tortall.net/
is a complete rewrite of the NASM assembler
---ESOTERIC ASSEMBLERS LANGUAGES---
Fake Assembly FakeASM
https://esolangs.org/wiki/FakeASM
an esoteric programming language
AttoASM
https://esolangs.org/wiki/AttoASM
assembler language designed for the AttoWPU experimental processing unit, as part of the WPU (Weird Processing Unit) concept (frozen project ?)
PISA assembly
https://www.cise.ufl.edu/research/revcomp/
https://www.cise.ufl.edu/research/revcomp/users/adickins/phpisa/phpisa.pdf
PISA Assembler is a tool to convert PISA assembly code to machine code for a Pendulum Chip. The Pendulum Chip is a reversible general-purpose processor
..hey, any esolang seems like assembler :V
---"WEB ASSEMBLER" STUFF---
WebAssembly WASM
https://webassembly.org/
"Assembly" for the web
ASM.js
http://asmjs.org/
a strict subset of JavaScript that can be used as a low-level, efficient target language for compilers
Cpython
https://en.wikipedia.org/wiki/CPython
an interpreter and a compiler as it compiles Python code into bytecode before interpreting it
Ewasm
https://github.com/ewasm/design
Ethereum flavored WebAssembly
...or Is JavaScript already an assembly language ???
https://www.hanselman.com/blog/JavaScriptIsAssemblyLanguageForTheWebSematicMarkupIsDeadCleanVsMachinecodedHTML.aspx
https://www.hanselman.com/blog/JavaScriptIsAssemblyLanguageForTheWebPart2MadnessOrJustInsanity.aspx
---CROSS ASSEMBLER STUFF---
64tass
https://sourceforge.net/projects/tass64/
64tass is cross assembler targeting the 65xx series of micro processors
MSX XAsm - Z80 Cross-Assembler for PC
http://marksletterink.com/msx/xasm/
Xasm is a cross-assembler that generates Z80 machine code on a PC
16-bit-CPU-transsembler
https://github.com/milanvidakovic/16-bit-CPU-transsembler
Converts x86 assembler code into 16-bit custom CPU
---HIGH LEVEL ASSEMBLERS---
HLA
http://www.plantation-productions.com/Webster/HighLevelAsm/index.html
a high level assembler
IBM HLASM
https://www.ibm.com/support/knowledgecenter/en/SSLTBW_2.4.0/com.ibm.zos.v2r4.e0zc100/hlasm.htm
another high level assembler
Wiz
https://github.com/wiz-lang/wiz
Wiz is a high-level assembly language for writing homebrew software for retro console platforms.
---MICROASSEMBLER STUFF---
The WLA-65816 Micro Assembler
http://www.villehelin.com/wla.html
is an open-source, cross-platform 65816 assembler
Micro-Assembly Language (MAL) Specification
http://www.ontko.com/mic1/mal.html
introduction to Micro-Assembly Language (MAL), the language accepted by the mic1 micro-assembler.
Mikrocodesimulator MikroSim 2010
http://www.mikrocodesimulator.de/index_eng.php
application where a microprocessor functionality can be simulated didactially
---DISASSEMBLERS---
Binary Ninja
https://binary.ninja/
is a reverse engineering platform
Hopper Disassembler
https://www.hopperapp.com/
lets you disassemble, decompile and debug your applications.
---IDE / FRAMEWORKS---
SASM SimpleASM
https://dman95.github.io/SASM/english.html
simple Open Source crossplatform IDE for NASM, MASM, GAS, FASM assembly languages
The METASM assembly manipulation suite
https://www.cr0.org/progs/metasm/
Metasm is a cross-architecture assembler, disassembler, compiler, linker and debugger. Written in pure Ruby.
Keystone Engine
http://www.keystone-engine.org/
is a lightweight multi-platform, multi-architecture assembler framework.
---QUANTUM ASSEMBLERS---
Open Quantum Assembly Language
https://github.com/QISKit/openqasm
a quantum assembler of IBM
QMASM: A Quantum Macro Assembler
https://github.com/lanl/qmasm
QMASM fills a gap in the software ecosystem for D-Wave's adiabatic quantum computers
---PROGRAMMING LANGUAGES RELATED TO LOWLEVEL STUFF (DIFFERENT THAN C/C++)---
Kaitai Struct
https://kaitai.io/
is a declarative language used to describe various binary data structures, laid out in files or in memory: i.e. binary file formats, network stream packet formats, etc.
Go vs Rust
https://golang.org/ https://www.rust-lang.org/
instead of c you can go or rust :V
Red Programming Language
https://www.red-lang.org/p/about.html
red is aiming towards Full stack programming :0
XOD
https://xod.io/
a visual programming language for microcontrollers
Turbo Rascal Syntax error, “;” expected but “BEGIN” <-(yeah the name of the PL)
https://lemonspawn.com/turbo-rascal-syntax-error-expected-but-begin/
for developing games for the 8/16-bit computers, with a focus on the MOS 6502 & the Motorola 68000, supporting the C64, C128, VIC-20, PLUS4, NES, PET and Amiga 500
---OTHER LOWLEVEL STUFF---
eXtremeDB Kernel Mode
https://www.mcobject.com/kernel_mode_database/
The first database management system designed explicitly to run in the OS kernel.
Rwasa
https://2ton.com.au/rwasa/
web server written in x86_64 assembly language
Multi-compiler
https://immunant.com/blog/2018/09/multicompiler/
it builds many functionally equivalent but internally different software variants, so that an exploit only works against one specific variant
Tutorial: Assembly Language with the Raspberry Pi
http://www.science.smith.edu/dftwiki/index.php/Tutorial:_Assembly_Language_with_the_Raspberry_Pi
Unconventional Computing
https://en.wikipedia.org/wiki/Unconventional_computing
System-level security research oriented linux distro
https://invisiblethingslab.com/
https://www.qubes-os.org/
The Ternary Manifesto
https://thebitcoinnews.com/the-ternary-manifesto/
Popcorn linux
http://www.popcornlinux.org/
expand the execution boundary of process beyond a single machine by allowing threads to run on distributed nodes.
Open-source firmware is the future
https://mullvad.net/en/blog/2019/8/7/open-source-firmware-future/
RISCVEMU: 128 bit RISC-V emulator
https://groups.google.com/a/groups.riscv.org/forum/#!topic/sw-dev/-M-GqeW_VgM
https://bellard.org/tinyemu/
https://github.com/kmsmith137/ch_vdif_assembler
128-bit stuffff
RedoxOS
https://www.redox-os.org/docs/
Operative system written in Rust where everything is a url
Ray assembler
https://github.com/sebhtml/ray
http://denovoassembler.sourceforge.net/
Parallel genome assemblies for parallel DNA sequencing
---OTHER ASSEMBLESQUE STUFF OUTSIDE COMPUTING---
Quantum-Language-Parse-Syntax-Grammar (not related to quantum mechanics)
https://dwmlc.com/ https://www.youtube.com/user/markkishon
https://github.com/lismore/MathematicalInterfaceForLanguage (like the godel numbering)
is an assembly version of the everday language, that is, a strict subset of the english language to improve the current legal language ( lawASM ??)
Psychomagic: The Transformative Power of Shamanic Psychotherapy (book)
Manual of Psychomagic: The Practice of Shamanic Psychotherapy (book)
https://www.amazon.com/Metagenealogy-Self-Discovery-through-Psychomagic-Family/dp/1620551039
The assembly language of the operative system that runs inside the family and the circuit of drives
Ayahuasca, Salvia and Iboga
https://en.wikipedia.org/wiki/Ayahuasca
https://en.wikipedia.org/wiki/Tabernanthe_iboga
https://en.wikipedia.org/wiki/Salvia_divinorum
The entry to some assembly level of reality...
Quantum Leap Advantage QLA
https://www.danpena.co.uk/
assembler language of the High Performance (not related to Gurdjieff) :0
Social Freedom crash course of Sushi Daygame
https://www.infinitemansummit.com/apply.html
Assembler language teached by the twelfth patriarch of the Social Freedom old lineage
Sequenced MaxVaCuaRo SMaxVCR
https://www.amazon.com/SEX-CRACK-CONVIERTETE-MAESTRO-SEDUCCION/dp/8467027363
Assemler Language of the human courtship
Notations of Alba Emoting (AE) and the Facial Action Coding System (FACS)
http://www.albaemoting.com/the-alba-of-emotions-3/
https://www.paulekman.com/
Both systems are 2 emotional assembler languages of the personality
Teargasm
https://whitetigertantra.com/
https://www.youtube.com/user/SchoolofSteveP/videos
It's what happen after you apply the millenary techniques of White Tiger Tantra of the old lineage of sensual shamans ;)
---FLOATING POINT AND RELATED MATHS STUFF---
New approach could sink floating point computation
https://www.nextplatform.com/2019/07/08/new-approach-could-sink-floating-point-computation/
The residue logarithmic number system: Theory and implementation ( paper )
https://www.researchgate.net/publication/4156476_The_residue_logarithmic_number_system_Theory_and_implementation
Hetero Base Arithmetic Operation
http://www.numbersystem.org/hetero-base-arithmetic-operations.html
Zot-Binary: a new numbering system with an application on big-integer multiplication
http://www.jatit.org/volumes/Vol48No1/5Vol48No1.pdf
Saturation Arithmetics https://en.wikipedia.org/wiki/Saturation_arithmetic
Lunar (or dismal) arithmetics 
Quote notation https://en.wikipedia.org/wiki/Quote_notation
Methodology of numerical computations with infinities and infinitesimals (paper)
http://www.theinfinitycomputer.com/
https://en.wikipedia.org/wiki/Hypercomputation
Tropical Arithmetics
https://mathalliance.org/wp-content/uploads/2019/01/SL-Talk-FIELDS-OF-DREAMS.pdf
A system where truncation and rounding are the same operation according to Knuth
https://en.wikipedia.org/wiki/Balanced_ternary
Double-Base Number System for Multi-Scalar Multiplications (paper)
https://www.iacr.org/archive/eurocrypt2009/54790501/54790501.pdf
Arborescent numbers: higher arithmetic operations and division trees (paper)
https://math.eretrandre.org/publications.html
Zero Displacement Ternary Number System... (paper)
https://www.researchgate.net/publication/258241283_Zero_Displacement_Ternary_Number_System_the_most_economical_way_of_representing_numbers
Symmetric level index
https://en.wikipedia.org/wiki/Symmetric_level-index_arithmetic
Santilli "symmetrized" Arithmetics
http://www.santilli-foundation.org/docs/10.11648.j.ajmp.s.2015040501.14.pdf
An Overview of Numeristics and Equipoint Analysis
https://kevincarmody.com/math/numeristicsview.html
---AN OPERATIVE SYSTEM INSIDE SOME INTEL PROCESSORS--- OMG!! :0
An Open Letter to Intel from Andrew Tanenbaum
https://www.cs.vu.nl/~ast/intel/
An open letter to Andrew Tanenbaum
https://hackernoon.com/an-open-letter-to-andrew-tanenbaum-883e1abe692a
Replace Your Exploit-Ridden Firmware with Linux - Ronald Minnich, Google
http://u-root.tk/
The Intel Management Engine: an attack on computer users' freedom
https://www.fsf.org/blogs/sysadmin/the-management-engine-an-attack-on-computer-users-freedom
Disabling Intel ME in Firmware
https://ecrsecurity.com/files/DisableIntelME.pdf
Intel Management Engine wikipedia
https://en.wikipedia.org/wiki/Intel_Management_Engine
--TOO MUCH IN THE LOW-LEVEL? GOTO THE OTHER END---
Luna
https://www.luna-lang.org
https://medium.com/@luna_language/luna-the-visual-way-to-create-software-c4db520d6d1e
is the world’s first programming language featuring two equivalent syntax representations, visual and textual
Eve (frozen project?)
https://github.com/witheve/Eve
https://hackernoon.com/how-eve-unifies-your-entire-programming-stack-900ca80c58a7
Programming designed for humans
Wolfram ( proprietary license right now :| )
https://reference.wolfram.com/language/
https://socalgis.org/2014/05/29/the-future-of-programming-wolfram-language/
symbolic computation, strong metaprogramming orientation
Wyvern
https://wyvernlang.github.io/
https://newatlas.com/wyvern-multiple-programming-languages/33302/
for writing high-assurance applications, type-specific language
Avail
https://github.com/AvailLang/Avail
https://letzgro.net/blog/new-programming-languages-what-may-shake-up-modern-development/
articulate programming,developing a domain-appropriate lexicon and phraseology for the job ( a library/PL hybrid? )
Hazel
https://hazel.org/
working with incomplete programs, typle-hole oriented
Gen
https://probcomp.github.io/Gen/
https://news.mit.edu/2019/ai-programming-gen-0626
probabilistic programming, modelling and inference
Unison
https://www.unisonweb.org/
https://www.theregister.co.uk/2019/09/26/unison_programming_language/
is a language with special support for building distributed, elastic systems
fiuu that was a lot ;)
---RELATED FORUMS---
https://assemblergames.com/
https://board.flatassembler.net/
https://forum.nasm.us/
http://masm32.com/board/index.php
https://retrocomputing.stackexchange.com/
https://www.dreamincode.net/forums/forum/112-assembly/
---OTHER SOURCES---
https://en.wikipedia.org/wiki/Comparison_of_assemblers
https://github.com/lurumdare/awesome-asm/blob/master/README.md
https://www.c64-wiki.com/
https://esolangs.org/wiki/Main_Page
https://steemit.com/programming/@himan12345/searching-for-programming-languages
https://en.wikipedia.org/wiki/Category:Non-standard_positional_numeral_systems
https://en.wikipedia.org/wiki/Open-source_hardware