Comments on: How KML Succeeds and Fails as a Web Format

By: Matthew Snape

Matthew Snape — Thu, 18 Feb 2010 12:29:32 +0000

To be fair KMZ does allow people to send GE content via email. This feature is a massive advantage for GE as a platform making it much more familiar to people. To drop KMZ entirely there would need to be some sort of secure alternative mechanism to do this.

It may be difficult to make a proxy, but surely that is exactly what is needed.

By: Ivan Boldyrev

Ivan Boldyrev — Sat, 13 Feb 2010 08:42:44 +0000

Many web servers (Apache and nginx) can send pre-compressed data. So, if you have both file.kml and file.kml.gz, server will send former or latter depeding on cilent’s capabilites, without any significant CPU load.

By: Glen Rhea

Glen Rhea — Wed, 03 Feb 2010 15:52:52 +0000

I think the area that kmz files excel in, other than compression, is offline access to resources. I’ve worked with some folks that just hand out a kmz file to their (disconnected) field agents and they work off that. All images and so forth are included in the kmz.

By: Jason Birch

Jason Birch — Wed, 03 Feb 2010 10:39:02 +0000

GZip/Deflate encoded KML may “work” with Google Earth but only, if I understand correctly, because Google Earth isn’t sending an appropriate accept-encoding header and is getting served uncompressed content instead. If this has changed recently, I’d LOVE to know about it.

Although KMZ (zip) is sub-optimal, and a pain in the ass for developers, it’s also a necessary evil for performance in many use cases. For instance, while I use KML for individual resources, any query that has the potential to return hundreds of rows uses a KMZ representation.

By: Richard Fairhurst

Richard Fairhurst — Tue, 02 Feb 2010 18:50:33 +0000

“web-based tools — like the Javascript support in browsers — lose all access to the data”

There’s a popular ActionScript 3 unzip library which is being used for .kmzs, so it’s not quite all. In general, though, yes, I’d agree.

By: Sean Gillies

Sean Gillies — Mon, 01 Feb 2010 19:57:36 +0000

The EPUB of the “GeoWeb”?

By: Keyur

Keyur — Mon, 01 Feb 2010 18:27:42 +0000

I concur. But as you mentioned - it’s too late in the game to ‘Free you KML’.

The web at large lives and dies by the goods and bads of HTML and JavaScript. And the geoweb with KML and KMZ.

By: Peter Rushforth

Peter Rushforth — Mon, 01 Feb 2010 16:47:25 +0000

KML isn’t well linked - how do you link to a specific placemark? Maybe that is just a function of the user agent behaviour, but the “geoweb” browser I’ve been using doesn’t support that.

Regarding compression - a very good point - leave the compression / decompression to the web server and client, but then you have to deal with resource (image) references using full URLs, not relative - which might also be related to the geoweb browser behaviour.