This highlevel diagram provides a view of the core technologies used in the OpenVista system "tech stack":

     OpenVista Technology Stack

Definitions:

• C# = programming language, implementation of the ECMA-334 specification
  
• .NET = Microsoft .NET framwork/execution environment
• Mono = Opensource/cross-platform .NET framework/execution environment
  
• Web Services = (originally SOAP or Simple Object Access Protocol) is a protocol exchanging XML-based messages over a network
• BR = Binary Remoting, a .NET native remoting protocol.
• New = Java applications written to operate and interact with database (dependencies on OVID technology, see below)
• MSC FileMan = Database management system (released to open source by Medsphere)
• Cache/GT.M = Application/database server environment (or the "M-engine")
• FM Projection = network-based read-only SQL projection of FileMan files
• OVID = Medsphere M/Java integration technology.  OVID is the code name.