The Allen Lab acquired an open qPCR instrument about a year ago. We were on the waiting list for a year, but they delivered. It’s about the same size as a conventional thermocycler, but it does more. It has blue LED illumination inside the heated lid and a green light sensor below. The result is that you can track fluorescence as you thermocycle. The key patents on qPCR just expired so I think they are safe from major litigation.
The instrument’s software is open and quite well designed. You connect to it with a USB cable and then use a browser to connect to its internal software. Once it is running, it doesn’t seem to need the PC connection.
My application has been to use qPCR instead of cyclecourse PCR for my students’ aptamer selections. We also used it to verify the DNA on the surface of microparticles. We can go down to about 10,000 molecules (probably limited by cheap plasticware that adsorbs some DNA; lo-bind plastic might lower detection limits further).
I did have to do a hard reset once after a failed update, but for the most part it has been a reliable instrument.