During the late 1990s, as networks formed the backbone of
businesses and Web browsers became the default means of
accessing new applications, it quickly became clear that system
“convergence” was the wave of the future. For facility and
security managers used to operating systems that resided on
proprietary buses and dedicated cabling, the move looked
daunting.  Today, the convergence of building-automation systems
(BAS) and information technology (IT) is an everyday reality
(Figure 1). New Web-based technologies are driving open
standards (e.g., XML) that are improving ease-of-use by
delivering information to those who need it when and how they
want it, whether via a desktop computer or a mobile device
(Figure 2). The rapidly decreasing cost of connectivity has
delivered a number of benefits to facility managers and their
organizations, including:    • More money to spend on
functionality, rather than dedicated wiring and phone lines.
• Increased revenue from higher-quality environments and
services.    •