**Invidious — summary (based on Russian Wikipedia)**
Invidious is a **free and open-source lightweight frontend for YouTube**, created by **Omar Roth** in 2018 and maintained by a community of developers. It’s written in **Crystal** and **JavaScript** and works on **Linux, Windows, and macOS**.
Invidious instances act as **server-side mirrors of YouTube**, using a custom *Invidious Developer API* that scrapes data directly from YouTube without using Google’s official API. It removes **ads**, **tracking**, and **recommendation algorithms**, offering a privacy-friendly experience.
The main public instance (invidio.us) shut down in **September 2020** after Roth stepped away from the project, though community instances remain active. In **June 2023**, YouTube sent a **cease-and-desist** letter claiming Invidious violated its API terms; developers rejected the claim, asserting they don’t use the official API.
Invidious is distributed under the **AGPLv3 license**, and its code is available at github.com/iv-org/invidious.
**See also:** NewPipe, Nitter.

Invidious — Википедия: https://ru.wikipedia.org/wiki/Invidious