OLS-Geocoder is an open source project that provides APIs for address cleaning, correction, completion, geocoding, and reverse geocoding. The Province of British Columbia is the prime committer and maintains a reference deployment called the BC Address Geocoder for use by government and the public at large. The BC Address Geocoder has processed over one billion addresses since its initial release in 2013. To see it in use by an application, visit Location Services in Action.
To find out how to integrate the BC Address Geocoder into your own application, please visit here.
To install OLS-Geocoder in your own environment, instructions are here.