I just completed phase I of something I call the Roc-Pi.
The Roc-Pi is a servo, LED, and block detector or in other words a multi-purpose stationary decoder that uses SRCP (Simple Railroad Command Protocol) as a communications protocol. While designed for use with Rocrail, it could be used with any good command software that is srcp capable..
The project web page is at http://rocpi.ae-tool.com
Rocrail is available at http://rocrail.net
The Roc-Pi is cheaper than commercial decoders. After totaling up everything, the Rocpi costs 1/4 of what commercial decoders cost. Commercial decoders cost about $15 per switch to implement plus the cost of the servo motor. The Rocpi is coming in at about $4 per switch. Less if it is just a LED or lighting controller. The reason is that relays for frog switching are not cheap.
If you are into model railroads and have been looking for a full featured switch or LED controller, this could be it.
For what it's worth.