You can now view Arbital through GreaterWrong: https://arbital.greaterwrong.com/
Some of Arbital's features are supported and some aren't; let me know in the comments if there's anything you're particularly missing.
Thanks to emmab for downloading the content.
Some of the math seems to be garbled, e.g. this page (compare with the version on obormot.net) and this page (compare with the version on obormot.net).