
www.geeksforgeeks.org
A computer science portal for geeks

www.draw.io
Professional, open source diagramming. Online or desktop, no registration.

www.deepl.com
Use the free DeepL Translator to translate your texts with the best machine translation available, powered by DeepL’s world-leading neural network technology. Currently supported languages are English, German, French, Spanish, Portuguese, Italian, Dutch, Polish, and Russian

valgrind
Valgrind is an instrumentation framework for building dynamic analysis tools. There are Valgrind tools that can automatically detect many memory management and threading bugs, and profile your programs in detail. You can also use Valgrind to build new tools.

SystemD
Its main aim is to unify service configuration and behavior across Linux distributions;[6] systemd’s primary component is a “system and service manager”—an init system used to bootstrap user space and manage user processes.

software.nasa.gov
NASA Software Catalog offers hundreds of new software programs you can download for free to use in a wide variety of technical applications.

quick-bench.com
Quick-benchmark is a micro benchmarking tool intended to quickly and simply compare the performance of two or more code snippets.

miro.com
Online whiteboard

https://www.onlinegdb.com/online_c++_compiler
online compiler and debugger for c/c++

https://www.jsonschemavalidator.net/
An online, interactive JSON Schema validator