The WIDE project, www.wide.ad.jp, is a research consortium among industry and academia. The WIDE project consists of more than four hundred active researchers from more than a hundred private companies and more than forty universities. The WIDE project operates the nation-wide R&D testbed, which is connected with many other R&D testbeds, and the NSPIXPs, that are the largest IXes in Japan. The main focus of the WIDE project has been IPv6 technology and has established an IPv6 testbed since 1998. Basically, all of the R&D activities in the WIDE project are based on the IPv6. This paper describes the overview of the WIDE project R&D testbed and the R&D activities, such as KAME/USAGI/TAHI projects.