118 Personal Content Experience: Managing Digital Life in the Mobile Age existing metadata fi elds of Web pages are today largely ignored by the 43 major search engines. 4.9 Yet Another Challenge: Interoperability In order to support mobile content across multiple applications, content types, and application and device generations, the interoperability must be thoroughly considered. Metadata can help here, too. In this section, we will discuss both personal content device ecosystems and application interoperability issues, considering both applications that are used concurrently, and the need to migrate between application generations. 4.9.1 Personal Content Device Ecosystem The consumer electronic (CE) devices offered to consumers are slowly being connected, especially those targeted at GEMS actions with per- sonal content. There are AV amplifi ers that connect to the Internet radio stations (Yamaha RX-V2700); many DVD/DivX players are capable of presenting streaming media (KiSS DP-600); and car audio system may contain a USB connector for easy listening of digital music from portable players (JVC Arsenal KD-AR770) or a cradle for Apple iPod. There are also devices that enable streaming content stored on a PC to a home stereo system or television set via a wired or wireless network (Pinnacle Showcenter 1000g). Not surprisingly, then, the development of personal content ecosystems is primarily driven by CE device manufacturers. The standards recently under development for interworking between components (such as DLNA, see below) are paving the way for truly functional device ecosystems. We assume that the personal content device ecosystem consists of one or more mobile devices – smart phones, portable music players, and the like – and one or more mobile stationary devices – such as set top boxes and home media servers. In the device ecosystem, all components need to connect to each other to perform personal content management operations. The simplest example of a personal content ecosystem is a PC that acts as a central home media server, performing back-end content management tasks. The server may be a personal computer located in 43 The Net crowds have started by re-using those fi elds with so-called microformats (http://microformats.org/about/), adding descriptive keywords that are not directly visible to users but add some semantics.