We deal with the problem of developing a software system which integrates collaborative real-time modeling and distributed computing. The main challenge is user-orientation: we need a collaborative workspace for geographically dispersed users with a seamless access of every user to high-performance servers. Wedescribe a particular system, Clayworks, that allows modeling of virtual clay objects and running computation-intensive deformation simulations for objects crashing into each other. To integrate heterogeneous computational resources, we adopted modern Grid middleware and provided the users with an intuitive graphical interface. We parallelized the computation of simulations using a Higher-Order Component (HOC) which abstracts over the Globus Web service resource framework (WSRF) used to interconnect our worksuite to the computation server. Clayworks is a representative of a large class of demanding systems which combine collaborative, user-oriented modeling with performance-critical computations, e.g., crash-tests or simulations for biological population evolution.