Google has just announced that Google Map Maker is being retired or, to put it another way, merged into Google Maps. Google Maps has slowly been gaining features that allow users giving feedback to provide more detailed information and Google plans to continue this trend until Google Maps’ functionality matches what is currently available in Google Map Maker. The Google Map Maker site will be shut down in March 2017.
Google Map Maker is not just a map editing tool, it also provides a community of dedicated mappers who provide support and a robust approval mechanism. Google suggests that members of this community move to the Local Guides Programme.
For those who don’t know much about Google Map Maker, it is a platform that allows members of the public to edit almost any feature in Google Maps. These edits then go through an approval process often largely managed by Google Map Maker users rather than Google employees. It has always been restricted to particular countries, but the list of countries has changed over time and has often included most parts of the world. A very significant proportion of the information you see in Google Maps came from members of the public via Google Map Maker, although this varies significantly by country and it is difficult to know just how much. In some countries, organisations have been formed around Google Map Maker by members of the public. See this Wikipedia page about the group Mapping Bangladesh for example.
Google has not been publicising Map Maker much for quite some time, preferring most feedback to come via the Google Maps interface. Google Map Maker has always been intended for those willing to put in extra effort, but for those willing to learn how to use it, it provides many map editing tools that are currently not available via Google Maps.
Another product that Google recently announced it would be merging with Google Maps is Panoramio.