A free and open-source implementation compatible with Advantage Database Server (ADS), discontinued by SAP.
https://github.com/FiveTechSoft/OpenADS
The goal is to provide a drop-in replacement for the Advantage Client Engine (ace32.dll / ace64.dll / libace.so) so existing applications — particularly Harbour/Clipper apps using contrib/rddads — keep working without recompilation.
One API, many backends — DBF today, any database tomorrow
OpenADS presents as ADS — your application talks to the same ACE entry points it always did — but that ADS surface is just the front door. Behind it, the very same API can be served by different storage engines:
Because the application only ever sees the ADS API, you run on DBF today and switch to PostgreSQL, MSSQL, or SQLite tomorrow if you outgrow flat files — without rewriting your business logic. The same Harbour/Clipper/FiveWin code, the same USE / dbSeek / tDatabase calls, now backed by a real database when you need concurrency, scale, or central administration. OpenADS is a scalable suite
