There is also TelegraphCQ, a competing project at Berkeley around the same time; TelegraphCQ was also built on top of PostgreSQL and its support for Continuous Queries seems essentially identical to Continuous Views here ("materialized views", "triggers", and "continuous queries" are all quite similar to each other in terms of the underlying technology needed). TelegraphCQ was commercialized as Truviso, bought out by CISCO a few years ago.
Thanks for the link, I hadn't seen TelegraphCQ previously. Following the trail, I also came across a couple other similar research projects relating to Stream-oriented DBs. Specifically, STREAM from Stanford and Cougar from Cornell, though it appears that all of these academic projects are dormant at this point.
PipelineDB certainly builds on work from Aurora, TelegraphCQ, Truviso, Streambase, and many other projects and companies. We have interacted heavily with many people from these projects to learn what worked (and didn't work) for them over the years, and hopefully to build on that in a pragmatic way.
To your point about promoting language standards, we've intentionally kept the syntax as close to SQL as possible in order to keep things simple. The goal has always been to give the broadest range of developers the simplest way possible to develop realtime applications using only SQL.
http://telegraph.cs.berkeley.edu/telegraphcq/v0.2/