Ingres
I worked with Ingres for seven years, but all that came to an end in 1999. I found Ingres to be a good tool, relatively uncomplicated and cheap to run. It's now less popular than it was in the eighties and nineties, but still in production and deserving of more attention than it gets. It is now an open source tool, it was not released initially under the Gnu Public License, but a community version has now been released under GPL v2.
You can find out more about Ingres at http://www.ingres.com
I had a lot of fun comparing Ingres with Oracle and writing a
customised checkpoint template which allowed parallel writing to
multiple tapes, if that interests anyone, let me know and I'll dig it
out.
You can reach me by email at
or you can text me on +44 7771 797568.