I would like to support Fast Infoset in some enterprise applications to reduce network traffic for XML and SOAP exchanges.
As documented on Wikipedia, there are Fast Infoset implementations for C# and Java.
According to OSS Fast Infoset Tools, implementations are already available on several platforms including Microsoft .NET and .NET CF, Sun GlassFish, BEA WebLogic.
It doesn’t look like it. So you have two choices if you want to use this in a Delphi program. You could use the .NET version via P/Invoke (or Hydra) or, if it wouldn’t be too huge of a task (haven’t looked at the size of the project) you could try porting it to Delphi yourself. If Java and C# can handle this library, Delphi can almost certainly make it into an “Even Faster Infoset”.