@Satsuma Psych, the YAML parser and emitter in Ruby, used for extremely important functionality in Ruby/Rails, is currently version 4.0.2.

Psych is essentially a wrapper for LibYAML.

The current release of LibYAML 0.2.5. The fact that the major version number of LibYAML is “0” implies that it is not a stable API or ready for production use.

@Lady huh thats an odd choice

@Satsuma very common in open source programming, and also terrible

nobody using Ruby/Rails for YAML processing necessarily understands (even from looking up Psych!) that they are effectively using an experimental processor (for example, its support of YAML 1.2 is piecemeal and incomplete), which defeats the whole point of semantic versioning