A riscv64 Linux booting in your browser with TinyEMU/JSLinux (© 2017-2019 Fabrice Bellard) and a static radare2 (© pancake) preinstalled.
Try r2 /bin/busybox, then aaa and pdf @ main. All r2 tools are available: rasm2, rabin2, rax2, ragg2, ...
Uploaded files appear in /mnt/tmp. The disk is streamed on demand, nothing is executed outside this page. Run resize in the shell after resizing the window, rotating the screen or toggling the keyboard. Add ?mem=256 to the URL for more guest RAM.