In this research, a C-Based Simulation Toolkit (CBST) was developed. It supports discrete, continuous, and combined simulation. CBST is a group of simulation support functions written in the language C. CBST functions are used within a specific framework similar to that of GASP IV. It employs the event scheduling world view for next event selection. The Runge-Kutta-Fehlberg integration method is used to update state variables. The simulation framework of CBST, descriptions of CBST functions, and details of program construction using CBST are described. Four models are developed using CBST and the results are analyzed. CBST is compared to similar software packages, namely GASP IV, DISC, and CSIM. CBST has more flexibility than GASP IV because it is C-based and because it offers resource management functions. CBST supports continuous and combined simulation, whereas DISC and CSIM do not. / Master of Science