As an alternative GC in Rust, you also have Josephine[1], which uses the SpiderMonkey[2] GC. It's cumbersome to use though[3] and should probably not be used outside of Servo.

[1]: https://github.com/asajeffrey/josephine

[2]: mozilla's JS VM

[3]: this is how you call a doubly linked list managed by the JS GC https://github.com/asajeffrey/josephine/blob/master/examples...