What is "openlayers"

Openlayers 2.x is a Javascript library that implements an API for developing dynamic map widgets on the web. The library provides tools to display and edit geographic information using pure Javascript, without server-side dependencies.

Openlayers supports a number of different access methods for spatial data, including Opengis Web Service Mapping (WMS) and Web Feature Service (WFS) protocols of Open Geospatial Consortium. Other supported geographic data sources include Google Maps, Openstreetmap, Bing Maps (formerly Virtual Earth) and Mapserver. See the page of live examples from Openlayers or the wiki documentation for more comprehensive details.

Openlayers is a project of Open Source Geospatial Foundation (Osgeo) and is distributed under a BSD license (also known as Clear BSD).

Tag use

openlayers and related scheduling issues could be more appropriate both in Stack Overflow SE and GIS SE. For Openlayers 3, use of tag openlayers-3.