To demonstrate some typical problems that you may run into when trying to link object files to Delphi, I picked two simple examples from the Abbrevia open source library. Abbrevia was originally a commercial compression library developed by TurboPower. They were selling multiple libraries—AsyncPro, Orpheus, and SysTools, which were later donated to the open source community. Their current home is at https://github.com/TurboPack.
For simplicity, I have included the complete Abbrevia repository in the code archive. All demos are already configured so you can just press F9 in Delphi and enjoy.
The first demo is called LzmaDecTest and it links in a single object file—LzmaDec.obj. That file is stored in the Abbrevia\source\Win32 ...