We present a collaborative attempt to build select toolboxes of Scilab using external Free and Open Source Software (FOSS) libraries. A C/C++ interface is written for each library. Scilab variables are transferred to C/C++ variables, computations carried out through one or more function calls and variables returned to Scilab. State of the art libraries, such as Octave, COIN-OR, OpenCV and IT++ have been used to build Scilab toolboxes. Scilab is selected as the frontend as it has a block based GUI to build models, called Xcos. Optimization, Signal Processing, Communication, Image Processing, Computer Vision, Signal Processing and Identification toolboxes are in advanced stages of development and use. Control Systems and Scilab to C toolboxes are in early stages of development.