Lack of TCO is a JVM problem. All JVM languages are incapable for this reason. It's a very hard problem to fix apparently, I remember even asking one of the Sun

Lack of TCO is a JVM problem. All JVM languages are incapable for this reason. It's a very hard problem to fix apparently, I remember even asking one of the Sun JVM developers at a talk at my university and he said one of the issues was the Java security model and stack ownership IIRC. This was a long time ago though so I may be incorrect. The problem remains hard though.