I am looking for a good range of Ethernet based I/O controllers that are flexible and expandable for tasks such as enabling and monitoring smart home functions.

I'm specifically looking for controllers that can be connected directly to the LAN and monitored via PHP, Linux bash scripting and or custom written applications.

As a developer, I'm wanting to avoid controllers that have limited inputs or that come with OEM software that does not allow manual programming or scripting. I simply want to be able to connect to the controllers IP address and port, then send commands when and where I want without having to install drivers or stuff like java.

Example: A nice cheap combined I/O controller that contains:

(a) Temperature Sensor inputs (suitable for logging solar hot water panel input/output temps and hot water cylinder temps and maybe room temperatures)

(b) Several Opto-Isolated inputs or simple dry contact sensors to monitor when solar pumps are running, hot water element is on/off, doors open closed, switches open/closed etc)

(c) Several relays for switching devices remotely/automatically (e.g. Enable electrical cylinder heating at controlled times or temperatures, switching lights remotely etc)

(d) Optional RS232 ports.

While we are at it, also an Ethernet mains power logging/usage controller using clip on current sensors (similar to the Ubiquiti mFI system) is also on the list.

Suggestions most welcome ?