SQL Anywhere and other members of the Adaptive Server family act as Open Servers. This means you can develop client applications using the Sybase Open Client libraries available from Sybase. Sybase Open Client includes both the Client Library (CT-Library) and the older DB-Library interfaces.

Sybase Open Client and Sybase Open Server exchange information using an application protocol called the tabular data stream (TDS). All applications built using the Sybase Open Client libraries are also TDS applications because the Sybase Open Client libraries handle the TDS interface. However, some applications (such as jConnect) are TDS applications even though they do not use the Sybase Open Client libraries—they communicate directly using the TDS protocol.

While many Open Servers use the Sybase Open Server libraries to handle the interface to TDS, some applications have a direct interface to TDS of their own. Sybase Adaptive Server Enterprise and SQL Anywhere both have internal TDS interfaces. They appear to client applications as an Open Server, but do not use the Sybase Open Server libraries.

SQL Anywhere supports two application protocols. Sybase Open Client applications and other Sybase applications such as OmniConnect use TDS. ODBC and embedded SQL applications use a separate application protocol specific to SQL Anywhere.

Application protocols such as TDS sit on top of lower-level communications protocols that handle network traffic. SQL Anywhere supports TDS only over the TCP/IP network protocol. In contrast, the SQL Anywhere-specific application protocol supports several network protocols, and a shared memory protocol designed for same-computer communication.