Chicken Scheme is a modern compiler for the R5RS Scheme programming language. It compiles Scheme code to C and allows easy FFI through foreign lambda interface.

The compiler supports many extensions to the base language and has a rich code library.

https://www.call-cc.org

C is a perfect translation target for many high-level programming languages. It can be easily used as a flexible intermediate language which is perfectly optimized, it can be built for almost any existing platform.

The following article shows a simple example of a FORTH to C translator. The author describes how to feed gdb with proper info about source language lines locations to simplity debugging and provide pretty backtraces in known IDEs.

https://yosefk.com/blog/c-as-an-intermediate-language.html

A perfect article about compilation of tail-recursive functions with the C language in the role of a target.

http://home.pipeline.com/~hbaker1/CheneyMTA.html

An enlightening article about linear type systems with a simple Lisp machine as an example.

http://home.pipeline.com/~hbaker1/LinearLisp.html

Полiт ОС - графическая оболочка для DOS с приятным глазу современным оконным интерфейсом. В полiт есть блокнот, плеер, двухпанельный менеджер файлов, менеджер контактов, игры и справочная система. Ввод в этой оболочке поддерживает английскую, русскую и украинскую раскладки.

Это компактное чудо написано на TurboPascal 7.0, а в коде может разобраться каждый - он открыт под GPL-совместимой лицензией.

http://bespin.org/~polit/

Updated and refactored Programming Language Zoo by Andrej Bauer.

Many examples of compilers and interpreters for various types of simplified programming languages: functional and imperative, lazy and eager, procedural and object oriented.

http://plzoo.andrej.com

A simple introduction to the type theory by Andrej Bauer.

http://math.andrej.com/2017/12/11/spartan-type-theory/

A video with the lecture mentioned in the previous post on the spartan type theory.

https://vimeo.com/286652934

Visopsys is an old but still alive OSdev project performed generally by only one author.

https://visopsys.org

A good introduction to the internals of Prolog.

https://www.amzi.com/articles/prolog_under_the_hood.htm

A perfect book on the art of solving problems by Sanjoy Mahajan. You can download the PDF version for free (see the "Open Access" tab).

https://mitpress.mit.edu/books/street-fighting-mathematics

Another book written by Sanjoy Mahajan on solving engineering and scientific tasks.

https://mitpress.mit.edu/books/art-insight-science-and-engineering

The free PDF copy is available on the "Open Access" tab.

I used many TUI-based TODO lists, there are plenty of them in GNU/Linux: todolist, ikog, todo.txt, yokadi and others. All of them are too simple for serious use, I think. But it looks like I've eventually found the golden middle - powerfull enough but still terminal friendly utility. Its name is Calcurse.

https://calcurse.org

One more tool looks very similar to Calcurse and definitely deserves your attention. This is Taskwarrior.

https://taskwarrior.org

Judy array is an effective sparse data structure implementing an interface of associative arrays.

http://judy.sourceforge.net

Электронная книга на русском с последовательным введением в язык Perl. Книга особенная, потому что фокусируется на примерах реализации алгоритмов, а не на тонкостях самого языка. Список примеров просто огромен.

http://mech.math.msu.su/~shvetz/54/inf/perl-problems/index.xhtml

Отличная книга в формате презентации про язык METAPOST.

http://mech.math.msu.su/~shvetz/54/inf/metapost/mpshort.pdf

ATS is a functional programming language inspired by ML and C++ with support of dependent and linear types. It also supports a subsystem for interactive theorem proving. As the author of the language wrote, ATS unifies implementation with formal specification.

http://www.ats-lang.org

DMVN - ресурс сделанный мехматовцами для мехматовцев с лекциями по основным направлениям и спецкурсам физики и математики, аккуратно сверстанными в LaTeX.

http://dmvn.mexmat.net

Sortix is a small POSIX-compliant self-hosting OS written from scratch and distributed under the terms of ISC license. What a nice mascotte!

https://sortix.org

LinageOS is an alternative Android distribution. It is fast, small and secure. I have installed it on my Xiaomi Redmi 3 today and it works perfectly!

https://lineageos.org/