NESticle is a Nintendo Entertainment System emulator written by Icer Addis of Bloodlust Software and first released on 1997-04-03. The program works in both MS-DOS and Windows. It went through several upgrades to the point where it could play most of the NES catalog of games with adequate accuracy, and included several features like save states, movie recording, screen capturing, a PPU and palette viewer, audio logging, and unlimited Game Genie codes. It was one of the first full-featured NES emulators, and remained popular for a long time because it was highly optimized and could emulate NES games at full speed, even on weaker hardware.
NESticle was my NES emulator of choice for several years because I always had second-rate computers, and it was the only one that could run on my PC at full speed. I remember not only playing many NES games for the very first time in this emulator, but also getting my first taste of NES hacking because it included ways to adjust graphics and patch ROMs. Although other emulators began surpassing it in terms of emulation accuracy, I had grown accustomed to the interface and kept using for years after it was discontinued. It wasn't until the various FCE branches were combined into FCEUX that I finally made the switch.