TileMill 0.4.1 [1], an open source MapBox project built on Mapnik, was released in August 2011 and is available for Mac OS X and Ubuntu. MapBox is a Development Seed [2] product that provides open source tools to create and host custom maps. "TileMill was built because we needed better tools for quickly designing beautiful maps with custom data," says Development Seed Developer Will White. "We kicked off development of TileMill at the beginning of 2011, and the first version was released on February 16th, 2011." White says that TileMill makes it easy to create highly customized, interactive maps for the web. "With TileMill, you design maps using Carto, a map styling language that looks just like CSS," White says. "TileMill allows you to export your finished maps as MBTiles files, which can be loaded into TileStream, an open source map server," he says.

TileMill’s detailed manual [3] will get you up and running after installation. The manual offers a primer on GIS, map projections, and coordinate systems and provides a tour of the TileMill interface. After launching TileMill in a browser (Figure 1), you will see several sample projects (Figure 2) and options to add a project or see the manual. If you open the Road Trip project (Figure 3), for example, you’ll see the toolbar, stylesheet editor, map preview, and a layers list. Here, you can adjust fonts or colors, zoom in or out, add new layers, and export the map. Clicking on the book tab in the top right-hand corner of the style sheet (shown in Figure 3) opens up a Carto reference menu (Figure 4).