I think the program which comes closest to M$Access is Rekall from theKompany.
It does not provide the database but can connect to all the usual suspects (mySQL, postgres, odbc etc.) and provides forms, scripting in Python and reports. I looked at it some months ago and found it intuitive (very access-like) but didn't have a real project to test it with. It was a pain to install on Debian at that time so I tested the windoze version. I don't know how install-friendly it has become in the meantime.
The software is dual licensed - commercial and GPL.
The sources to the GPL version are freely available from
Ready-to-install binaries however will cost you 15 British Pounds. For evaluation purposes you might want to download a trial version of the commercial package from www.thekompany.com
After installing the trial version on windoze I had problems trying to install the GPL version so you might want to use a de-installer tool or use a windoze box which you do not care about.
Have fun and if you give it a bash I would be very interested to hear how you get on.