Zeus Technology Ltd [1] is a company based in Cambridge, UK. Once well known [2] for their Zeus Webserver, they are now focused on their flagship product ZXTM [3], a high performance internet traffic manager. Scala fits into their product by using their existing feature of Java Extensions, allowing people to write Scala code to manipulate and route network traffic. They recently published an article about using Scala and ZXTM together [4] and, according to their experience, the result works very nicely indeed.
If you want to experiment, free developer licenses [5] are available to Scala developers.
Links:
[1] http://www.zeus.com
[2] http://news.bbc.co.uk/2/hi/business/699733.stm
[3] http://knowledgehub.zeus.com/internal/2007/02/07/what_is_zxtm
[4] http://knowledgehub.zeus.com/articles/2009/06/30/scala_zxtm_and_java_extensions
[5] http://www.zeus.com/landing/zxtm-app-developers.html