GROWL: A lightweight grid services toolkit and applications. The GROWL project is a framework in which we can develop and evaluate Grid services in environments familiar to many scientific programmers. A need has been identified for a client toolkit which can provide very light-weight but extensible access to Grid resources (owls are very light and quiet for their size). We are therefore initially creating libraries in C/ C++ and R, interfacing to a set of existing services derived from HPCPortal, DataPortal and InfoPortal which are part of IeSE, the CCLRC Integrated e-Science Environment. It should be possible to install this library on a variety of client workstations with a minimum of additional software.