pnkfelix (from Mozilla) has been doing lots of investigation into custom allocators[0], custom GCs, and embedding Rust into places where a GC is already active. He also recently published some blog posts outlining the problem of GC interop[1][2]. Quoting aturon[3]:<p>&gt; To be clear, a major goal of this project -- outlined in the earlier blog posts -- is &quot;GC as Interoperation Feature&quot;. That is, we want to embed Rust code into contexts with existing GCs (such as the V8 or SpiderMonkey Javascript engines), and so Felix is trying to find ways to accommodate a relatively wide range of GC approaches, with maximally safe, efficient, and ergonomic support on the Rust side.<p>Might be a while off before good support for custom GCs for pure Rust code, but it&#x27;s definitely being thought about.<p>[0]: <a href="https:&#x2F;&#x2F;github.com&#x2F;rust-lang&#x2F;rfcs&#x2F;pull&#x2F;1398" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;rust-lang&#x2F;rfcs&#x2F;pull&#x2F;1398</a><p>[1]: <a href="http:&#x2F;&#x2F;blog.pnkfx.org&#x2F;blog&#x2F;2015&#x2F;11&#x2F;10&#x2F;gc-and-rust-part-1-specing-the-problem&#x2F;" rel="nofollow">http:&#x2F;&#x2F;blog.pnkfx.org&#x2F;blog&#x2F;2015&#x2F;11&#x2F;10&#x2F;gc-and-rust-part-1-spe...</a><p>[2]: <a href="http:&#x2F;&#x2F;blog.pnkfx.org&#x2F;blog&#x2F;2016&#x2F;01&#x2F;01&#x2F;gc-and-rust-part-2-roots-of-the-problem&#x2F;" rel="nofollow">http:&#x2F;&#x2F;blog.pnkfx.org&#x2F;blog&#x2F;2016&#x2F;01&#x2F;01&#x2F;gc-and-rust-part-2-roo...</a><p>[3]: <a href="https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;rust&#x2F;comments&#x2F;3zqtoc&#x2F;gc_and_rust_part_2_the_roots_of_the_problem&#x2F;cyp0gfu" rel="nofollow">https:&#x2F;&#x2F;www.reddit.com&#x2F;r&#x2F;rust&#x2F;comments&#x2F;3zqtoc&#x2F;gc_and_rust_pa...</a>