Wireless mesh networks are currently emerging as a promising technology for broadband ubiquitous networking. Typical applications range from home broadband Internet access and community networking to wireless metropolitan area networks. Many companies are currently active in this field with proprietary solutions mostly based on the IEEE 802.11 family of standards. At the same time, there are considerable efforts in academia aiming to provide real-world prototypes and testbeds based on open source software and off-the-shelf technologies. This article provides a survey on the most relevant hardware and software platforms that can be used to build a WMN testbed.