GameMaker is my favorite visual programming language:
You could insert custom blocks of Delphi but for the most part it was blocks of objects.
http://dist.alternativeto.net/s/bbb84d61-31f2-de11-8cae-0022...
http://dist.alternativeto.net/s/bbb84d61-31f2-de11-8cae-0022...
Correction: I remember the underlying scripting language being GML (GameMaker Language). Maybe Delphi was embeddable into early versions of GameMaker? I also know that you could link plugins as DLLs...
It was a lot of fun and I found it impressive how easily you could throw things together. It was a nice change of pace from learning C++, where I had not yet gotten into graphical libraries.
On a related note, I also experimented a bit with RPG Maker, which allowed for some simple scripting and made it very easy to quickly create environments using sprites. https://en.wikipedia.org/wiki/RPG_Maker