Mapquest, the granddaddy of web mapping platforms, has been losing market share ever since Google Maps burst on to the scene. Google Maps’ tile-based (aka “slippy”) map interface and API caused many to adopt Google’s offering over Mapquest for integration with web sites as well as for daily use.
Mapquest has since turned over a new leaf and is offering a tiled map based off of OpenStreetMap data. Announced in 2010, the OSM-sourced map is just one of a few developer-friendly moves the company has recently made.
If you want to get started using Mapquest maps in your blog or personal web page, they have a simple to understand page on how construct your map using their Map Builder application. You can then embed maps into your WordPress blog using their plugin. If you want something more advanced, you can use their Open APIs to incorporate their OSM tiles and data into your application.
And if you don’t want to use Mapquest’s API as the framework for building your application, you can always use the Mapstraction library and still use the tiles and some of their other data services.