On my Wind River blog, you can now find a description on how we have used the Eclipse TCF (target connection framework) to build the Simics GUI. Or rather, the connection between the Simics GUI and the Simics simulation process. It is actually quite revolutionary what you can do with the TCF, compared to older debug protocols. In particular, TCF lets you combine many different services across a single connection.
For Simics, the result looks like this:
Note that all services, and all GUI views, are driven across a single connection to the Simics process. We do not need a special debug connection for each target system, and we do not need to separate debug and analysis and general Simics things. They all travel across the same single connection, thanks to the service orientation of TCF.
It is important to note that TCF is a completely open-source project under Eclipse, and it is available for any and all debugger and tools vendors to use.