Magnetic resonance spectroscopy (MRS) offers a wealth of information to the biochemist or radiologist. Metabolite concentrations, J-couplings, pH, ion concentrations and gradients, temperature, etc., can all be obtained, in situ, from well-defined volumes in the human body, and in a totally non-invasive way. However, simple methods such as peak area integration or automatic line fitting in the FT MR spectrum are still relied on for routine MRS data analysis. The disadvantages of such methods are tolerated in order to keep processing fast and simple for the spectroscopist. The authors have developed a graphical user interface, in which advanced time domain signal processing methods are combined. They present a complete software package for routine MR data analysis, called MRUI, enabling the use of advanced parameter estimation algorithms with incorporation of prior knowledge via simple menus and spectral displays, in a fashion similar to the spectroscopist's spectrometer software.