[atombender]

Pure speculation, but it's quite possible that it was written in Delphi (the last iteration of Borland's Turbo Pascal lineage), which had a fast single-pass compiler that did very little optimization. Delphi was very popular in Germany in the late 1990s and early 2000s.

[imtringued]

Delphi makes things worse because the code it generates is incredibly ugly. The code listings use the C++ std and it looks straightforward so presumably it is just good old C++.

[vintagedave]

It could equally be C++Builder. Back in those dates, the C++ compiler used a similar backend to Delphi - it was derived from Delphi's originally, since the two products interop and you can use both languages in one app. Today's C++Builder uses LLVM.

[mark-r]

Borland had a C++ compiler too, but it was never nearly as popular as the Pascal-based Delphi.