[perplexes]

I'm surprised no one has mentioned Esper yet: http://www.espertech.com/esper/

Esper does exactly this - you run streams of events over it and it continuously executes SQL to see if it matches. If so you can:

- run code

- make new streams

- store the results

Esper's been doing this kind of thing for 9 years now.

[ak4g]

Esper is really curious. I looked at it while getting a feel for the general landscape of streaming data tools in late 2013 - to be clear, it was a very cursory look, on the timescale of a few hours at most. I quote what my final take-away was at the time:

> Seems good but... such a weird project. Codehaus, svn, not high activity, but consistent, stable releases for five years. Maybe just not the kind of thing webdevs get into? Not sure if that's a strike against or not.

With the demise of Codehaus it looks like they've moved to github:

https://github.com/espertechinc/esper

But oddly they don't seem to have migrated their svn history, and the README implies they don't plan to... I certainly hope they didn't lose it when Codehaus shut down. There was, as noted, already 9 years worth of code changes in that repo. That would be unfortunate.