This paper focuses on the implementation of heterogeneous Mobile Ad Hoc networks (MANET). A heterogeneous MANET is a wireless network setting without a fixed infrastructure where participating devices may be of different kind (e.g., desktop, laptop, or palmtop computers), may not share the same operating system (e.g., Linux, Windows NT, or Windows CE), and may not share the same wireless technology (e.g., Bluetooth, or IEEE 802.11b). We describe the design and implementation of a prototype for the OLSR routing protocol, targeting multiple operating systems, devices, and radio technologies. We choose a proactive routing protocol to obtain optimal routes in a dense network with slow mobility patterns and to ease the portability task to the heterogenous environment. We also optimized the OLSR protocol, making it more reactive to topology changes.