System is decomposable in three major data pipelines:
- Data Archiving (Adds new data to Historic Archive)
- Filtering Pipeline (Filtering and delivery data in realtime)
- Playback Pipeline (Filtering and delivery data from Historic Archive)
And PHP is used for many parts of these.
- Frink, tweetrmeme’s framework
- Stone: foundation of in-house test tools, Hornet and Storyteller (they probably open source a fork named Storyplayer).
Unfortunately I wasn’t able to find more details about these. Anyway, here is the presentation: