Until recently if you wanted to create a fast interactive map to use on your website you had two main options - design it in Flash, or use Google. With the prevalence of mobile devices, for many users Flash isn't an option, leaving Google and a few competitors (like Bing). But we are developing open source technologies in this space that provide viable alternatives for serving fast interactive maps online - ones that often give users more control over map design and the data displayed on it.
TileMill, our open source map design studio, now provides interactivity in the latest head version on github. Once you design a map with TileMill, you can enable certain data in the shapefile to be interactive.
When you export a map into MBTiles, a file format that makes it easy to manage and share map tiles and which you can easily export any map made in TileMill to, all the interaction is stored within the MBTiles file. This allows us to host interactive maps that are completely custom designed - including the look and feel and the data points - that are as fast as Google Maps.
Yesterday, Tom MacWright gave a talk about designing fast maps and other emerging open source interactive mapping technologies, and specifically comparing them to Google, at the Where 2.0 Conference, a leading annual geo conference. If you're interested in learning more about this and weren't at the conference, check out his slides, which are posted on our blog.