This blog describes the porting of a medium-sized application (~250 kloc) from D7 to Lazarus. It uses PostgreSQL as database, and the connection is being ported from DB Express (D7) to SqlDB (Lazarus).
Above, Lazarus 0.9.30-0 + FPC 2.4.2 editing Rednaxel's ERP, RNGE 3, running on Windows XP (32-bit). Below, the same screenshot -- same project, same source code -- taken on Ubuntu 10.10 (32-bit).