With Adobe Flash now gone, there’s no way to play SWF files. For sites like The Web Archive this can be troublesome as many of the old Flash-built websites will no longer be viewable. Ruffle will help them out:
Ruffle is a Flash Player emulator written in Rust. Ruffle runs natively on all modern operating systems as a standalone application, and on all modern browsers through the use of WebAssembly. Leveraging the safety of the modern browser sandbox and the memory safety guarantees of Rust, we can confidently avoid all the security pitfalls that Flash had a reputation for. Ruffle puts Flash back on the web, where it belongs – including iOS and Android!
Note that this is still a Work in Progress. Actionscript 1 & 2 Support is just over halfway, but support for AS3 is still only at 5%.