Arena
Arena was a web browser developed by the W3C. It has been used by the W3C for testing support for HTML 3 and Cascading Style Sheets. Arena is no longer update. The Yggdrasil Computing then took over the role of developing the browser. Development of Arena web browser stopped in late 1998, with the final release being on 25 November.
Other testbed environments are likely to take over Arena's role within W3C. The W3C now use the Amaya browser as their new testbed.