Fuel cell technology is used to react fuels such as hydrogen or methanol with oxygen via an electrochemical path, thereby generating electricity. While the technology has been available for decades for specialty applications, it has undergone much more rapid development in recent years, spurred in part by the promise of a hydrogen economy. Many companies participate in the field, at various stages of the product cycle (research through mature products). Websites for these companies are collected in this category. For more information about the principles behind fuel cell technology, see the corresponding Science category.