It looks as if it is not a big deal to use the MySQL protocol rather than the client library. I can now log in that way, so the rest should follow, and I am working on the changeover. The current MySQL protocol has been around since version 4.1.
Given that Piotr has, I think, already done the same work at protocol level for Postgres, that SQLite is public domain, and that a similar API can be done with ODBC, we should be able to cover a fair range of systems without falling foul of GPL. Steve