The iSmell or iSmell Personal Scent Synthesizer was a computer peripheral device developed by DigiScents in 2001. The prototype connected to a personal computer via USB or serial port and was designed to emit a smell when a user visited a web site or opened an email. The device contained a cartridge with 128 "primary odors" which could be mixed to replicate natural and man-made odors. DigiScents had indexed thousands of common odors, which could be coded, digitized, and embedded into web pages or email.
In 2006, the iSmell was named one of the "25 Worst Tech Products of All Time" by PC World Magazine, which commented that "[f]ew products literally stink, but this one did--or at least it would have, had it progressed beyond the prototype stage."