Mapstraction is a library which provides a common API for several disparate JavaScript mapping APIs, including those from Google, Yahoo! and Microsoft, to enable switching from one to another as smoothly as possible. The aim of Mapstraction is mainly to protect companies building commercial products on top of Google Maps from changes to terms and conditions, the introduction of ads, or the emergence of a competing library with better maps, different imagery or preferable licensing terms. Initial development of Mapstraction was made possible with the generous support of Nestoria.

Mapstraction additionally fills some holes in each provider's current offerings (taking advantage of existing open source solutions where possible) to normalise the feature set across platforms. In the future, Mapstraction will also talk to OpenStreetMap for people who want to build maps without restrictions on derived works.