The Sybase product line includes servers and tools for building servers:
Adaptive Server Enterprise is a database server. Adaptive Server Enterprises manage information stored in one or more databases.
Open Server provides the tools and interfaces needed to create a custom server application.
An Open Server application can be any type of server. For example, it can perform specialized calculations, provide access to real-time data or interface with services such as electronic mail. An Open Server application is created individually, using the building blocks provided by Open Server Server-Library.
Adaptive Server Enterprise and Open Server applications are similar in some ways:
Both servers respond to client requests.
Clients communicate with both Adaptive Server Enterprise and Open Server applications through Open Client products.
But they also differ:
An application programmer must create an Open Server application, using Server-Library’s building blocks and supplying custom code. Adaptive Server Enterprise is complete and does not require custom code.
An Open Server application can be any kind of server and can be written to understand any language. Adaptive Server Enterprise is a database server and understands only Transact-SQL.
An Open Server application can communicate with non-Sybase protocols, as well as with Sybase applications and servers. Adaptive Server Enterprise can communicate directly only with Sybase applications and servers; however, Adaptive Server Enterprise can communicate with non-Sybase applications and servers by using an Open Server gateway application as an intermediary.