Have a look at this document from Lincoln:http://www.lincolnelectric.com/assets/global/Products/K1525-1/e452.pdf
Invertec process is included in lincoln units only (research and development by Lincoln), its basically smart current control independent of wire feed speed based on the short created at the tip. Invertech uses current waveform control ( interval and time) independent of the wire speed feed.
Miller has similar techniques that can produce similar results with their Accu Pulse technology see the following link:http://www.millerwelds.com/products/advanced/pdf/AMS-Process-Capability.pdf
hope that helps
Its just arc control called different names by different companies, talk to their reps and get some more info.