KGen98 was a new version of KGen rewritten from scratch, with better compatibility, more features and higher quality stereo sound. KGen-X was an aborted rewrite of KGen which was never released to the public.
This was a DOS based emulator and ran on high end 486 or faster hardware, but required at least a Pentium for full speed. Another emulator called Genecyst was released around the same time by Bloodlust Software and a friendly rivalry began. This was the first Mega Drive emulator to feature accurate digital YM2612 emulation as opposed to other efforts which attempted to approximate Genesis sound and music via the then popular OP元 chips of AdLib and Sound Blaster-compatible cards.
KGen was Steve Snake's original attempt at a Genesis emulator, written because at the time the only existing emulator, Genem, ran slowly and had poor sound quality.