Baidu Maps

Baidu Maps is a desktop and mobile web mapping service application and technology provided by Baidu, offering satellite imagery, street maps, street view ("Panorama" - ) and indoor view perspectives, as well as functions such as a route planner for traveling by foot, car, or with public transportation. Android and iOS applications are available.
Baidu Maps is available only in the Chinese language and before 2016, it offered maps only of mainland China, Hong Kong, Macau and Taiwan, the rest of the world appearing unexplored. Currently Baidu Maps also offers maps of various other countries. It was reported that more than 150 countries would be supported by the end of 2016. Baidu uses map data supplied by NavInfo, MapKing, Here, LocalKing and OpenStreetMap.
In 2016, it is reported that Baidu Maps has over 348 million monthly active users, and will "transform from a Chinese map provider to a world map provider and become the Chinese brand that provides global services for mobile travel applications", which also outlines Baidu's plans for global expansion.
Coordinate system.
Baidu Map uses a variant of web Mercator projection for slicing map data into tiles, with distances expressed in degrees. It's associated with an underlying latitude-longitude reference. However, the reference uses the BD-09 coordinate system, which adds further obfuscation to the already obfuscated national standard in China, GCJ-02 (which in turn is defined in terms of the "de facto" standard around the world, WGS 84). Baidu alleges that adopting BD-09 "protects users' privacy".
The Baidu Map API documentation specifies that "real" (WGS-84) GPS coordinates must be converted via a coordinate conversion interface. An HTTP interface, JavaScript API, Android SDK, and iOS SDK are available.
The JavaScript coordinate conversion API is demonstrated online by Baidu, but without any reverse (to GCJ-02) conversion capabilities. Open source implementations in R and various other languages exist, implemented in a manner much like the reverse GCJ-02 algorithm.
BD-09's lat-lon coordinates are derived by scrambling a polar version of GCJ-02 coordinates and adding a fixed offset:
from cmath import polar, rect
from math import sin, cos, pi
coords = complex
def gcj_bd(gcj: coords) -> coords:
 r, θ = polar(gcj)
 r += 2e-5 * sin(gcj.imag * pi * 3000 / 180)
 θ += 3e-6 * cos(gcj.real * pi * 3000 / 180)
 return rect(r, θ) + (0.0065 + 0.006j)
Street view service.
The street view service of Baidu Maps was first launched on August 21, 2013. This is a list of cities supported as of March 11, 2015:
Censorship.
India.
In June 2020, the Indian Government blocked Baidu Maps as well as 58 other Chinese apps citing national security concerns. This came after clashes in the Galwan Valley between the People's Liberation Army Ground Force and the Indian Army.