At the CeBIT 2000, GMate introduced the YDK1000, the Yopy Development Kit. Without a physical keyboard this device looked very different from later versions. It came with an embedded Linux operating system and the W Window System. Later also precompiled versions of the X Window System and the IceWM window manager became available.
The first official model in the Yopy line of PDAs was the YP3000. It introduced the clam shell design with a full-Qwerty keyboard, and featured a 3.5 inch TFT screen. It also came with the X Window System and IceWM.
One of the features of the YP3500 is a CDMA module, so it can be used as a mobile phone. In 2003, Wi-Fi was widely used in Korea, and so the YP3700 targeted this environment with an additional Wi-Fi module.
As of March 2005, Gmate has stopped producing and selling the Yopy PDA, and has closed down its official web sites.
Using the Linux operating system, the Yopy became capable of running a variety of open source software. Some developers are using software they compile on their own.