Biophysical and agro-ecological models often have a high demand of soil data that is not always met by available soil data sources. A way to overcome this problem is to infer the missing information from the data available by means of pedotransfer functions (PTFs). A range of PTFs were derived from various authors to estimate soil properties that are difficult to quantify via in situ measurements or laboratory measurements on samples. Such PTFs are being evaluated over a variety of soil types. The PTF research is a continuing process, driven by the high demand of hydrological data due to agro-environmental modelling. A software library, comprehensive of existing PTFs and easily extensible to implement new pedotransfer functions can be very effective for use in modelling applications and to assess the performances of the various PTF's in specific situation. Current software technology allows developing software units (components) complying with such requirements. Components encapsulate solutions to modelling problems and make such solutions available for use in custom developed applications of different complexity. The issue of providing easy access to a large set of PTFs into one, extensible component, was dealt with here. The component (namely,SoilPar.dll) implements approaches for estimation of a number of soil properties via alternative PTFs. The PTFs implemented have been extracted from peer-reviewed sources which have presented the most widely adopted methods for soil properties estimation. The component was developed for the .NET platform of the Windows operating system using C#. Software features and the scientific background are fully documented in a HTML-style help. Sample Windows applications, a web service, and a web applications are made available as source code to show how to use and extend the components. The component is distributed through the site http://www.sipeaa.it/tools.