Yes, there are several options to access Adabas without Natural, depending on the platform your client application is on and what platform your Adabas database is on (mainframe, Linux, Windows…).
Adabas Client for Java enables Java applications to access Adabas data. Adabas REST client enables REST web service calls to access Adabas data. Adabas SQL Gateway enables SQL access to Adabas data using any JDBC/ODBC client.
Adabas Direct Calls can be coded in many language tools (C, COBOL, Java, Assembler, PL/1, etc). See the Adabas documentation and community Knowledge Base for additional details (try “direct calls Adabas” search).
In addition, adapya (Adabas API for Python) is available from GitHub - see the Tech Forums Developer Centre (ADAPYA in GitHub).