Summers is "Haikutec" on Twitter, and according to an 10/19 update, the project is "Already heading towards 600 verses..."
A renga is a poem written through a collaborative effort, in this case, the collaboration comes from poets around the world not just from those in Bath. You too, can take part. All you need do is submit a short 2 or 3 line verse. Follow the directions at Area 17.
If you're interested in learning more about the Japanese form of renga, a good place to start would be Jane Reichhold's AhaPoetry page on renga.
Photo courtesy Alan Summers.