Highbase provides high availability clustering for the MySQL database server.
It's written using shell scripts and other open source programs for special purposes (arp spoofing, etc.).
Monitoring of MySQL was done through mon's mysql.monitor perl script until recently. We now have a contributed C program to perform the monitoring.
There's a paralell (with very slow progress) erlang source tree.
These details are provided for information only. No information here is legal advice and should not be used as such.