Retro Computing

Protoweb - Proxy for the old net. Some function just as good as they did back then
The Old Net - Website that connects to Archive.org's wayback machine. Also has a proxy.
Frogfind! - A search engine powered by DuckDuckGo that supports old computers.

Interesting Github/lab projects

Web Rendering Proxy - Use your modern computer to allow an obsolete one to use it.

Image Tools

Photopea - A free online photo editor.
Dither it - A free website that allows you to dither photos. Can save a lot of space.