How can I use publish/subscribe without requiring any administrator involvement?

Question

Scenario

I have a Windows service that is in charge of listening for various things and act accordingly. Most of the time this service modifies the database in some fashion (adding, removing and cancelling items). This is on the servers side and requires no user involvement. The client side is quite simple. Each user (5-10) each use an application to work on the items inserted by the Windows service.

Problem

The issue is that the clients are working in a disconnected state. What I mean by that a client could reload their list of items needing to be worked on and 5 minutes later actually begin their work.

Also, due to various issues no administrative assistance must be required in order to install the client application. This rules out libraries such NServiceBus (or any library requiring the use of MSMQ) and WCF (seems like so because it requires the use of opening up URLs using netsh http add urcl.

I'm not looking to send messages to clients. All I'm looking for is an easy way to have the Windows service poke each subscribed client instructing them to reload their list. I do realize that I could simply create a background thread (or the like) and refresh every n minutes but there's really no sense in doing that (IMO) if nothing has happened in the last few hours.

Edit

Researching some more it appears I can use raw sockets for this. Will update once I get something working.

Answer 1

Take a look at 0MQ, it might meet your requirements.