ActionScript 3 is specified by the proposed ECMA-262 edition 4.
Other formats for the reports are listed on the Haskell wiki.
JavaScript is standardized as ECMAScript in ECMA-262.
The specification appears to have been last updated for VB 11.0, with only some updates made to it since then. VB 7.0 was the first version to have a language specification. The old website may have documentation for VB 6 and earlier.
All specifications are listed on the YAML site and maintained on GitHub.
The Zig Language Reference is published for all versions and maintained on GitHub.