It looks pretty much identical to the Turbo Pascal IDE for anyone that's feeling nostalgic and wants to write some yellow on dark blue code.
Even better - Free Pascal comes with Free Vision, which is mostly compatible with Turbo Vision. Turbo Vision was the toolkit Borland provided that would let you write your own text-mode GUI apps using the same widgets used to build the Turbo Pascal IDE.
I don't think the Free Pascal IDE is related to this
If you check the website demos and the "dos.h" source on GitHub, this is a library for making GUI apps whose UI has the appearance of being made with MS-DOS.
Unless I am misunderstanding the connection you're trying to make, which is also possible
Even better - Free Pascal comes with Free Vision, which is mostly compatible with Turbo Vision. Turbo Vision was the toolkit Borland provided that would let you write your own text-mode GUI apps using the same widgets used to build the Turbo Pascal IDE.