When we are searching for the correspondence between build numbers and version numbers, we might get this URL pointing to a KB article maintained by VMware:
https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1014508
However, the following article written by some independent author is a LOT better! It's easier to read, up to the point and clear! Thumb up!
http://www.virten.net/vmware/esxi-release-build-number-history/
Credit to that article's author!!
Quite a shame that VMware can't produce such a good quality for its own KB articles.
NB: This is a duplicate of my document at https://communities.vmware.com/docs/DOC-31366 for the record.