It was an installer, installed all the DLLs, which if you bundled with your application, meant you were golden to run it as-is. Though you are technically correct that you need them, I think my statement still stands: You just need to bundle the required DLLs and OCX files and you're golden.
That's not very comforting for the dozens of times (that I personally experienced) that the developer didn't make sure it was "golden" and instead left a headache on the end user.
As long as you used the bundled installer, everything worked. If you didn’t, you’d need to bundle extra components but, IIRC, component selection was automatic - any DLLs, VBXs, and OCXs used would be detected and bundled.
I think the installer itself was licensed from a third party.