> Does it mean sources can be retrieved from CVS and just built,  without
> needing the 3.10 release tag?

No.  The CVS trunk is most probably broken, as all recent bug-fixing
was done within the release branch.

A quick guide to tags and branches in the OCaml CVS:

- Releases have tags of the form "ocamlNNNN", e.g. "ocaml3100" for 3.10.0

- Release branches (where bug-fixing takes place) have tags of the form
  "releaseNNN", e.g. "release310" for the 3.10 branch

As of today, if you're tracking the CVS, I recommend using the branch
"release310", or "release309" if you need the old Camlp4.

- Xavier Leroy