Thanks! Sort of like Emsisoft?
Someone may come along and correct me if I am wrong but this is how I remember it.
GData used to be Kaspersky and Reliable Antivirus (RAV), I was involved with the business of bringing localized GData to the USA way back under the branding 'eXtendia Antivirus - AVK Professional'. Microsoft bought out RAV to use for Microsoft Security Essentials and GData transitioned to their own in-house engine as the secondary one around that time I believe. Eventually GData transitioned to what they are now.
Emsisoft, I believe that was A-Squared Anti-Malware or something. I forgot, but I used to use it when it was a stand alone. Emsisoft is basically A-Squared, Mamutu, Bit Defender in it's form today.
That is my approximate remembrance of things.