This is a small hack of OpenLayers GIS mapping program that allows you to navigate genomes. Below is rice chromosome 7 with a single track added. As with openlayers, one can add as many tracks as desired. Images are rendered from a perl program by E. Lyons and J. Kane. souce (for js stuff) available via SVN:

svn checkout https://genome-browser.googlecode.com/svn/trunk/ genome-browser

or tar ball