With the development of low cost hardware for wireless networking based on IEEE 802.11b, wireless networks are an emerging technology. Using these wireless techniques outdoors it is possible to build a community network not dependent on any provider. In the Netherlands such a network is being set up in and around Leiden. Using low cost network boards, home-built antennas and open source software the volunteers of the Wireless Leiden Foudation are able to lay-out an infrastructure for the inhabitants of Leiden at a very low cost. All kinds of applications (profit and non-profit) are using this entirely wireless network.