[Omnipresent]

This is pretty neat. Wonder if they're using some data catalog under the covers for the search screen or is it all custom built.

[GavinAnderegg]

It looks like ArcGIS, which is what my city of Halifax, NS also uses: https://catalogue-hrm.opendata.arcgis.com/

[booleanbetrayal]

It is ArcGIS. Here is their Emergency Operations Center overlay:

https://bouldercounty.maps.arcgis.com/apps/webappviewer/inde...

You get used to refreshing this page during down-slope, windy, red flag days.

[simonw]

Looks like that one is using https://hub.arcgis.com/

Another common platform for these is https://dev.socrata.com