I mentioned tabbed because it's used to run multiple instances of a program that doesn't support tabs just to achieve the same result.

I am looking for a tabbed-like container but for another purpose. Sometimes GUI apps require certain (might be even fixed) window sizes. In case of tiling window management this is not always possible:

1. the tile size reserved for said program is smaller and the window size of that program is forcefully decreased by the window manager

2. the tile size reserved for said program is greater and the window size of that program is forcefully increased by the window manager

I need a container program that could run GUI apps inside and honor their window size requiremens:

1. if required size wouldn't fit in the container window area - the container shall display scrollbars

2. if the container window size would be greater, it shouldn't enlarge the GUI app window size against its will

i think the usual way with tilers is to configure the wm to render this certain app's windows as floating (i.e. the app decides how big it is).

That's exactly what I'm trying to avoid. I want to use vanilla tiling wm, just have a container that takes as much screen space as wm gives it, but manages other GUI app inside to honor its window size requirements.

i think herbstluftwm supports this:
containers that can then also contained floated apps.

I've been trying to find a standalone container program. So I could use it with any window manager.