KML is a staple of the Google Earth API, but its support in the Google Maps API is kind of tacked on.  Google Earth uses the Plate Carree projection.  Google Maps uses the Web Mercator projection.

For features where the vertices are explicitly known they can be reprojected dynamically or on a remote server.  However, this does not work for rasters-- unless they are warped/reprojected they will be quite off, and warping/reprojecting rasters is expensive.

Can it be done?  Sure.  But even best case, you're parsing a XML file (bottleneck on CPU) and reprojecting coordinates / rebuilding geometry with scalar code (bottleneck on CPU).  Worst case you're warping and reprojecting a raster (reaaaally bottlenecks on CPU), or just displaying it wrong.  KML has different features and object types.

Maybe there should be an equivalent of KML for Google Maps and the Web Mercator projection, but KML itself isn't it.  It's the wrong coordinate system and stores far too much data that should be stored in a compact and efficient binary format as XML text.

I'm not against it being added, but it should be noted it's for a different product and thus incurs performance costs.  On the other hand, the true analog of KML for the Google Maps SDK, the raster/vector representation for the standard map type, hasn't been released and it doesn't look like it ever will be.  Disappointing either way.

All of this is true, however... since it's support in the Google Maps Javascript API is excellent, it's a frustrating dichotomy.

 Issue 5597  has been merged into this issue.

 Issue 6734  has been merged into this issue.

 Issue 6696  has been merged into this issue.

(No comment was entered for this change.)

 Issue 6658  has been merged into this issue.

Will this ever be implemented? Javascript & Android have these already...