Largely in response to learnings from terrorism-related events, there's a new protocol for first responders that involves their entry into buildings before they're fully cleared of any danger. Commanding a situation like that requires GPS-like 3D indoor mapping technology where no GPS exists.
The Google Maps API team maintains many Google Maps APIs and SDKs. Manually tracking updates across the various sets of Release Notes presents a challenge for developers. Google now offers auto-updates to Maps Release Notes via RSS feeds. RSS feeds for all Maps and Places APIs are available.