Introduction
Streaming, Cloud based gaming and the power of a simple modern web browser is getting more and more impressive, more and more platform are getting into this sector and of course the Amiga world already has a few solutions.
Ant Stream
A cloud based gaming service with over a thousand licensed retro games across an array of retro consoles, and of course one of the platforms and games it features is Amiga, indeed, "Ant" kinda comes from Zool characters, the platform runs on Windows, Mac, Android, and Linux. It also has extra features like tournaments, and leaders boards so you can compete with people online. It also currently free.
The Amiga Workbench Simulation
Javascrip simulation of various Amiga Workbench OS oh how they look and each function, not really a full system online, but you can get to see how AmigaOS would looks over the decades and get a good idea how AmigaOS works.
Online / Browser Scripted Amiga Emulation (SAE)
Thanks to ever advancing web tech with Html 5 and Javascript it now possible to emulate complete gaming system, this of course now includes the Amiga. It still early days of this setup and you need to have quite a powerful computer to run this type of emulation but it's bound to only get better. The Internet Archive web site did add nearly the whole Amiga library of Amiga games, 10,000 titles on their site, however many have since been removed due to licenses and the number has gone down to 4,000 with many of them just being demo versions of popular Amiga games.
http://scriptedamigaemulator.net/
vAmiga (VAmigaWeb)
Original designed emulator for MacOS, it has since been ported to web based version, a number of updates have made it one of the more user friendly options to use. You can use the official roms, but also allows use of the AROS replacement rom.
https://vamigaweb.github.io/ - vAmigaWeb project which focusses to bring Amiga Gaming to web browser.
https://vamiganet.github.io/ - VAmiga main home page
https://dirkwhoffmann.github.io/vAmiga/ - Code and version for MacOS
https://www.neoartcr.com/vamiga/index.htm - A Pre-setup version with a fairly easy to use, user interface and loads of pre config Amiga games / Demo ready to go.
Other Cloud Based systems
There are a few other interesting project that both have big Amiga fans involved, Amibian.js (https://jonlennartaasenden.wordpress.com/) & FriendOS (https://friendos.com/) both are Remote desktop protocol systems and have some recognisable systems for Amiga fans. It be interesting in the future where this leads and if a true Cloud based only solution will ever take off.
Media
https://www.youtube.com/watch?v=ONjbA-hkpL8 - Easy ways to play Amiga games
https://www.youtube.com/watch?v=DtrRTXCZSDs - Antstream review by Gametechplanet
https://www.youtube.com/watch?v=bbdYnw_kvKU - Amiga in a Browser
Further Reading
http://www.chiptune.com/ - Another online scripted Amiga system that gives you a web site like Amiga system and lets you play some Amiga demos
https://vamigaweb.github.io/ - vAmigaWeb project which focusses to bring Amiga Gaming to web browser.
https://amiga.oszx.co/ - SAE website with more Amiga games
http://wab.com/ - Classic Amiga Demos and new Demos done in Javascript
http://blog.stef.be/amiga-javascript-bigger-plan - Intresting read on UAE.js projects and ideas
https://www.stef.be/bassoontracker/?file=demomods%2Flotus20.mod - BassoonTracker Amiga music player in js
https://www.youtube.com/watch?v=bbdYnw_kvKU - my video on the subject (a little out of date now)