Getting data from an external process is the usual scenario.
However, you have to obey the Data Adapter interface, based on "subscribe" and "unsubscribe" to data "items". Hence, depending on the interface supplied by your external process, your Data Adapter may have more or less work to do.
For a HelloWorld-like demo, you can read from your external process and forward each line through an "update" call for the "greetings" item.
We have no .net specific tips, other than the remarks provided in the API documentation, available at http://www.lightstreamer.com/docs/ad...AdapterAPI.chm