This paper discusses the design, development and operation of two tools intended for B-RNAV operations: the enhanced AUGUR system, which was commissioned by EUROCONTROL, and the Global Positioning System (GPS) Performance Monitoring System (GPMS), commissioned by National Air Traffic Services Ltd. (NATS). Both tools were implemented by STASYS Ltd., with support from Delft University on AUGUR algorithm issues. AUGUR, a Predictive GPS Receiver Autonomous Integrity Monitoring (RAIM) system, performs complex calculations and provides an easy-to-interpret Internet-based interface to aid aircraft operators with the use of GPS. Enhancements to AUGUR have been implemented to meet user requests and the requirements of a future Joint Aviation Authorities (JAA) Temporary Guidance Leaflet (TGL) on the airworthiness and operational approval for the use of Area Navigation (RNAV) systems in European airspace designated for Precision RNAV (P-RNAV) operations. The GPMS records output from a variety of GPS UE, has a real-time interface, performs simulations based on logged data, and permits remote analysis. The work carried out consisted of specifying a system to meet the safety study recommendations, choosing hardware, analysing interface requirements, and developing systems and software. These tools are now in place to help with GPS B-RNAV operations, and provide a layer of safety for both en-route flight and GPS-based non-precision approach operations in European airspace.