The single click, task orientated interface could easily be the product of an entirely different parent. However below the surface the EPOC operating system is at the heart of both. When Psion originally developed EPOC for their Series 5 PDAs they had the foresight to split the User Interface from the base layer using a powerful object orientated middleware. This foresight has allowed Symbian to embark on the development of three separate flavours of EPOC targeted at tight product niches. The Quartz User Interface employs a list based, paper like metaphor with single click activation.
Applications display their data as lists, clicking on items opens their details.
The other important component of the paper metaphor is that when a user switches away from a screen the data is saved. Parallels could be drawn between the Palm interface and Quartz, but there are significant differences. Firstly Quartz does not have a specific space for handwriting, rather the whole screen is available. Similarly the shortcuts for application activation are displayed on screen, meaning that customisation is done in software not hardware. Secondly, Quartz is design to have telephony built into the device.