JSLinux is an emulator written by Fabrice Bellard. It enables you to run Linux in your web browser.
There are versions with Fedora 33 or Buildroot, console or X Windows.
Both Fedora and Buildroot have the GNU toolchain installed so you can write and build C or assembly language programs and run them. There is objdump to disasemble the binary code. Both include sample C and Python programs.
Fedora of course has a lot more software included. Including emacs.
See the main JSLinux page for other versions.
You can also download the underlying TinyEMU and Linux disk images and run them on your own computer.