The ability to track the real-time location and movement of items or people offers a broad range of useful applications in areas such as safety, security and the supply chain. Many systems that track subjects in real-time outdoors such as GPS and mobile phone triangulation have severe limitations when tracking individuals in a smaller area, such as a room, building or garden. GPS devices require line of sight with satellites to be tracked correctly, meaning devices cannot be tracked indoors or in some areas surrounded by tall buildings. The degree of accuracy to which GPS provides location information is also inadequate for applications that monitor areas with specific boundaries between where an individual is allowed and where they are not. Mobile phone tracking is expensive and works only in more developed areas in the range of multiple cell towers. Position estimation, to within an average of fifty metres, is much too inaccurate to track subjects over a small area. Implementing a location determination system using received-signal-strength (RSS) has the advantage that the system can work indoors, however the cost of implementation is rather high and the complex network infrastructure may need constant maintenance. Radio Frequency Identification (RFID) is an automatic identification technology which has seen increasingly prominent use in tracking, however problems also exist here with regards accurate tag location determination. WLAN fingerprinting is arguably the most successfully used technique in systems on the market now. We provides here an overview of common techniques & commercial products used in tracking people and objects within indoor environments and outline the Locator framework which allows the tracking of people indoors using active and passive indoor localisation techniques.