[candiodari]

I figured we need a summary in here. Open source MS access alternatives (indexed from other comments):

There's MS access of course https://products.office.com/en-au/access

Open Source

  LibreOffice Base https://www.libreoffice.org/discover/base/
  Kexi https://www.kde.org/applications/office/kexi/
  Gnome DB http://www.gnome-db.org/
  Lazarus (better for programming, worse for DB) https://www.lazarus-ide.org/

Web based

  Oracle Apex https://apex.oracle.com/en/
  Google AppMaker https://developers.google.com/appmaker/ ($10/user, only paid users can access app)
  Bubble.is https://bubble.is/
  Quickbase http://www.quickbase.com/
  Caspio https://www.caspio.com/
  Airtable https://airtable.com/
  Zoho Creator https://www.zoho.com/creator/
  Rajic https://www.ragic.com/
  Knack https://www.knack.com/

Other desktop apps

  FileMaker Pro http://www.filemaker.com/products/filemaker-pro/ (predates everything else in this list, beautiful, if somewhat limited, app)
  Embarcadero (Borland) Delphi https://www.embarcadero.com/products/delphi
  DataFlex http://www.dataaccess.com

Really more programming frameworks, but sort-of fit the bill

  Python Django https://www.djangoproject.com/
  Ruby On Rails http://rubyonrails.org/

[meredydd]

I think https://anvil.works belongs in your "Web based" category as well.

(Although perhaps with the same note as Lazarus - fundamentally, it's a [Python!] programming environment with a DB attached, rather than a DB with a programming environment attached.)

[wx196]

Outsystems, Mendix, Alpha Anywhere, m-Power, Wavemaker, Microsoft PowerApps and many less known others.

[kk_cz]

as a former Delphi programmer - seeing Lazarus as MS Access alternative really hurts. :)