It's DC!
I got it from this page @Unreal Software German Wiki.
I think it's Peter because it has that frame that Unrealsoftware uses.
This is for all curious peeps like me.
--- Edit ---
Sorry if I disrespected your privacy, DC. But it was at a public Wiki so...
He said that when he posted his picture at the "About" section.
I think I didn't check the About section in that time. the first time I saw that section it had no pic of DC.
And qhy doesn't DC answer this? I searched and DC answered to a post that had a 'Easter-egg-image" - Unreal Software logo and his face as background.