The other year I tried to implement a GC on top of an existing scripting language to handle circular dependency cases. A big problem however was the existing sy

The other year I tried to implement a GC on top of an existing scripting language to handle circular dependency cases. A big problem however was the existing system for referencing objects wasn't particularly well designed for this particular case (e.g. no roots, no thread safety), and I couldn't come up with a solution I found satisfactory and fool-proof. The fact the author had so many problems with GC bugs is somewhat reassuring. Would be interesting to see a GC-less Nim in a production use-case.