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This thread is ignoring the entire "industrial controls" family of hardware and software. Some things are different because they need to be. Example -I would never consider using windows in an application that has safety implications. In fact it's shrink wrap license specifically disallows this use. Some examples of a safety application can be found here

Rockwell automation

Emerson Process

AE Solutions

Sometimes the right tool needs to be used.

L85E

Yes, that's a $20,000+ PLC there, boys

The requirements for functional safety in programming industrial safety critical systems are well known, and are very different from the requirements for programming. Boiler flame safety systems are commonly microprocessor based now, and rarely if ever fail. Here are some links explaining some of the requirements.

PLC® vs. Safety PLC – Fundamental and Significant Differences
FM Global Class 7605 Approval Standard for Programmable Logic Controller Based burner Management Systems
IEC 61508 Functional Safety

This level of care is mandated by insurance companies and legislation, due to the history of boiler explosions early in the 20th century. Searching "Boiler Explosion", and "Functional Safety" will lead to many references on this subject.

Had a friend that was in Shanghai for about a year. Worked for Rockwell. So a US/Canana/UK based company that has a Beijing office might be your best shot.

PLCs (Programmable Logic Controllers) are the traditional way to solve the interface between software and hardware sensors. This is done in industrial computing and control all the time (Factories, manufacturing machines, robotics, etc). The sensors and actuators are connected to the Digital/Analog Inputs and Outputs of the PLC. The input signals are converted into variables (with ADC) that can be read like any other variables. The output variabels are converted back into the appropriate valtages and currents (0-10 VDC or 4-20mA). The I/O modules also do error, short circuit, wire break, etc. checks. Basically PLCs take out the hassle of having to build the hardware interface between the real world to the software.

Most of them are programmed in a graphical language called Ladder diagram (like relay logic dagrams in software). Some of the more advanced ones can be programmed in C or other 3rd generation languages. There is actually a standardised set of languages to program them, Structured Text is the one that is most C/Pascal/Basic like (see IEC 61131-3). There are libraries etc to support all the conventional control issues and yes you can build your own.
See companies like Siemens Automation and Drives http://www.siemens.com/, Rockwell Automation http://www.rockwellautomation.com/, Bernecker & Rainer Industrial Automation http://www.br-automation.com/, Schneider http://www.schneider-electric.com/ for more information.

You should really add a mushroom-head pushbutton guard to this, so you don't frob it accidentally.