W3C has announced that the latest preview release of the next major version of EPUBCheck, v5.0.0 is now available. “For the first time, this version fully implements the new rules in EPUB 3.3 (W3C Candidate Recommendation Draft).”
The full change log is available on the EPUBCheck preview release page and users are encouraged to test this version as they prepare their workflows for EPUB 3.3
The W3C news piece gives details of how to report bugs and comment via the issue tracker. Our congratulations to all involved.
EPUBCheck is maintained by The DAISY Consortium on behalf of W3C.